The excellent L-leucine producing mutant No. 218, derived from a biotin requiring glutamic acid producing strain, is methionine and isoleucine auxotrophic. A suboptimum growth condition made by adding a limiting amount of isoleucine was necessary for the maximum production of L-leucine. On the other hand, methionine was indifferent to the productivity if sufficiently supplied for growth.
Biotin of more than 50 μg/liter caused the accumulation of L-leucine; less than 50 μg/liter, however, gave a drastic change in accumulation pattern from L-leucine to L-glutamic acid. Strain No. 218 produced 28mg/ml of L-leucine after 72 hr cultivation when 13% glucose was supplied as a carbon source, thus giving the yield of 21.6%.
Effects on L-leucine production of concentrations of inorganic salts, pH, temperature and aeration were also investigated.

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An efficient partial image storage method is required for an image revision system to store a huge amount of retouched image data. This paper proposes and evaluates a framework for an image revision management system, which uses the JPM file format to store differential elements between two versions of the image. Two data storing approaches are considered, one stores replaced elements after the edition, and the other stores replaced elements or differential elements adaptively. These approaches are evaluated with four different kinds of edit operations: blurring, edge emphasis, character writing, and adding noise. Since the combination of JPM's image object organization and JPEG 2000's efficient region compression is effective for image revision management, our proposed system can save storage capacity and network bandwidth in the image revision management system.

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To participate in the Standard Disaster Robotics Challenge in the Disaster Robotics Category at the World Robot Challenge in the World Robot Summit 2020 Fukushima Competition, we have developed a main-replica type

using which anyone can easily control the disaster robot. The two student operators finished second in the competition despite having only five hours of practice time. In this study, we present the results of surveying the essential elements of a for disaster response robots, and introduce the that is designed and implemented based on the survey.

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A new identification method using the second order plus time delay model for the automatic tuning of the PID and a simple and explicit tuning method are proposed. We present a relay feedback test combined with a P to identify the process using the second order plus time delay model. Thus, the difficulty to determine the initial proportional gain is overcome. Since the proposed identification method uses the second order plus time delay model to identify the prodess, it can incorporate more various processes such as underdamped and high order processes than the identification method using the first order plus time delay model. In addition, a simple and explicit tuning relation for the second order plus time delay model is proposed in this paper. This tuning relation shows almost the same performance as the optimal tuning parameters. The proposed method needs no numerical technique and shows good performances in both simulation and experimental study.

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The discrete time preview control problem is investigated in this paper in the framework of frequency characteristics. Along this line, the most attractive is the Zero Phase Error Tracking , abbr., ZPETC, which can reduce the phase characteristics of the overall system to zero for all frequencies. However the previous methods may produce an excessive gap between the gain of the overall system and unity, which is ideal gain characteristics. This paper proposes a new ZPETC, which is designed so as to minimize the maximum of the gain gap over a specified frequency range under the condition of zero phase error. Our contribution is that the proposed ZPETC can bring the gain of the overall system closer to unity than the previous methods, which is demonstrated by a numerical example.

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The tuning of PID controllers is of great importance for process industries because it directly affects productivity, operability, and operating cost. Performance monitoring and maintenance of PID controllers are also serious issues for anyone seeking to maintain profitable plant operation. This paper presents a novel PID tuning methodology using a reference trajectory and a simple optimization-based algorithm. In particular, the proposed methodology is readily able to handle process constraints and to obtain PID tuning parameters using optimization directly. An application of this tuning method to a liquid level in a drum is shown, which has a constraint to avoid flooding of the liquid level. Furthermore, the method was implemented in DCSs of two kinds and was demonstrated successfully by simulation of a Crude Distillation Unit preflash drum.

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In this paper, we propose an identification method to estimate the second order plus time delay (SOPTD) model parameters. The proposed method obtains the parameters of the SOPTD model directly using a time weighted integral transform and a least square method, so model reduction steps can be avoided to tune the PID . It can also be applied regardless of the initial states while almost all previous identification methods require the assumption of zero initial states. Through extensive simulations, it is proved clearly that the proposed method gives acceptable estimation performances whether initial states are zero or not. Moreover, it shows an acceptable robustness to the disturbances and measurement noise.

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This paper analyzed the effects of the model predictive

for the iterative learning control tasks of the human motion. In our assumptions, the predictive most affects the beginning of the iterative learning trials. Some experimental results indicate an example of this case, and they show a possibility of the effects of our assumption.

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This paper pertains to the direct adaptive Proportional–Integral (PI) control of nonlinear chemical processes. A simple yet effective PI parameter tuning algorithm, which has different structures separated by a defined zero-level set of process output errors, is derived. This algorithm enables a PI to control chemical processes in an interactive and autonomous way by simply observing the process output errors. To show the stability of the resultant PI control system, a rigorous analysis involving the use of a Lyapunov approach is presented. The effectiveness and applicability of the proposed direct adaptive PI control schemes are demonstrated by considering the control of a nonlinear continuous stirred tank reactor (CSTR) in the presence of a plant/model mismatch, an unmeasured disturbance, and parameter variations. Comparisons with several conventional PI controllers and an indirect adaptive Proportional–Integral–Derivative (PID) are performed for performance evaluation. Simulation results indicate that the proposed PI control scheme in associated with the derived parameter tuning algorithm is promising and that it offers flexibility and excellent capability for the direct adaptive control of nonlinear chemical processes.

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This paper describes a small and inexpensive

using Linux for control experiments and practical training of robots. Inexpensive components were selected for ease of use in practical training. The power supply circuit is designed to be used with servo motors. A base board was made to integrate necessary functions.

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This paper presents a new relay feedback method to guarantee the accuracy of the enhanced relay feedback method. The new method uses the integrals of a process input and output to tune Proportional-Integral-Derivative (PID) controllers automatically even if the process input and output are contaminated by measurement noises and disturbances. This feedback method uses a new disturbance estimator and a new noise magnitude estimator to remove the effects of noises and disturbances on estimates of frequency response data. Simulation and application to a real system to control liquid level demonstrate that the proposed methods provide fairly accurate ultimate data of the process and that the PID

tuned by the proposed method achieves control faster and with less overshoot than the conventional auto-tuning strategy based on the conventional relay feedback method.

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An analytical tuning method for a PID cascaded with a lead/lag filter is proposed for FOPDT processes based on the IMC design principle. The is designed for the rejection of disturbances and a two-degree-of-freedom control structure is used to slacken the overshoot in the set-point response. The simulation study shows that the proposed design method provides better disturbance rejection than the conventional PID design methods when the controllers are tuned to have the same degrees of robustness. A guideline of a single tuning parameter of closed-loop time constant (λ) is provided for several different robustness levels.

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PID controllers have been widely used in many chemical processes. Because they have only three control parameters and their physical meanings can be easily grasped. However, it is difficult to tune those parameters practically, since the process dynamics often change due to operating conditions or various disturbances. For this problem, a design method of robust PID controllers has been already proposed by the authors in order to guarantee the stability of the control system. However, as that control method is conservative, the desirable setpoint response can not be always obtained. In this paper, a design scheme of a self-tuning pre-filter is proposed to supplement the robust PID based on the two-degree-of-freedom control scheme. According to the proposed scheme, the transient property for the setpoint response can be improved keeping the robust stability. Finally, the proposed scheme is experimentally evaluated on an air pressure control system.

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Design the nuclear reactor power control system in this paper to cater to a nonlinear nuclear reactor. First, calculate linear power models at five power levels of the reactor as five local models and design controllers of the local models as local controllers. Every local consists of an optimal contrived by the toolbox of Optimal Designer (OCD) and a proportion-integration-differentiation (PID) devised via Genetic Algorithm (GA) to set parameters of the PID . According to the local models and controllers, apply the principle of flexibility model developed in the paper to obtain the flexibility model and the flexibility at every power level. Second, the flexibility model and the flexibility at a level structure the power control system of this level. The set of the whole power control systems corresponding to global power levels is to approximately carry out the power control of the reactor. Finally, the nuclear reactor power control system is simulated. The simulation result shows that the idea of flexibility model is feasible and the nuclear reactor power control system is effective.

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A spring-lumped mass dynamic absorber system with internal vibration disturbance sources is constructed for active vibration control. The self-organizing fuzzy is employed to control the vibration amplitude of the main mass. This approach has learning ability for responding to the time-varying characteristic of the disturbance inducing vibration. Its control rule bank can be established and modified continuously by on-line learning. The experimental results show that this intelligent effectively suppresses the vibration amplitude of the body with respect to the external disturbance.

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A 2-degrees of freedom PID is designed for a maneuvering acceleration control system. This design method is based on the combination of PID and IPD . Results show that (1) IP is superior to PI for the damper loop , (2) the selection of PI or IP as for the acceleration depends on the tradeoffs between the responsibility and the reduction of inverse response.

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