• Journal of Biosystems Engineering
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• v.22 no.2
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• pp.127-136
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• 1997

This study was accomplished to develop a pneumatic granular applicator that can be attached to the conventional ride-on rice transplanter. Operating conditions of a metering device for the applicator were determined so as to obtain the required discharge rate of granules for field application. The shape and size of diffuser was selected for the applicator and the spacing between diffusers on a boom and the boom height were determined as an optimal application condition for uniform distribution. The diffuser spacing of 1m for the fertilizer and the diffuser spacing of 0.8m for the pesticide at the boom height over 0.8m were acceptable.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.32 no.5
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• pp.176-182
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• 1983

This paper derives a newly neveloped analytic optimal condition to minimize the operating cost of a generation system in the aspect of Power System Planning, When the system includes pumped-storage units. The analytic optimal condition is derived by defferentiating the analytic cost function, Which were obtained by assuming the load and generating as Gaussian random variables, with respect to the variations of pumping energy. The condition is resulted in very simple form and various optimization techniques can be used. The simulation results of a case study were compared with the results of the conventional methods to prove the usefulness of the algorithm.

• Korean Chemical Engineering Research
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• v.47 no.2
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• pp.157-162
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• 2009

In this paper, the density, viscosity and solubility are measured to know the physical properties of dye. By changing the concentration of dye solution, the density change of the dye solution was very small and the viscosity of the dye solution was increased. Also, by changing the temperature of dye solution, the density change of the dye solution was increased but the viscosity of the dye solution was decreased. Solubility of dye conducts under the changing the salt and concentration of dye. In 20 wt% of dye and 15 wt% KCl, the amount of dye crystal is maximal. Also, batch salting-out experiments were performed with various conditions to know the optimal operating conditions of dye crystal. Under the various experiments, optimal operating condition was found based on amount of dye; added 15 wt% KCl, $25^{\circ}C$ temperature, 100 RPM, added at once.

• Fire Science and Engineering
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• v.22 no.1
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• pp.16-23
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• 2008

In this research, the visualization experiment for a scaling tunnel was conducted to establish the optimum fire protection system in tunnel fires. In order to find the optimal operating condition of jet fan with the fire, the characteristics of smoke propagation was considered to find the optimal operating condition of jet fan at the time of tunnel fire, the concentration of smoke was measured experimentally for various jet fan position and it's operating condition. As a result, when jet fan in the vicinity of fire operates at the upstream, the back-layering of the smoke should be considered with separation distance from the fire source. The distance between the jet fan and the fire should be longer than 50 m. On the other hand, when the vicinity jet fan operates at the downstream, the back-layering of smoke does not occur, but stratification is not maintained because the smoke dispersion occurs at the downstream due to the operation of the jet fan.

• Journal of Power System Engineering
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• v.13 no.6
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• pp.43-50
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• 2009

If an internal combustion engine is operated by consolidated control, the minimum fuel consumption is achieved satisfying the demanded objectives. For this, it is necessary that the engine is operated on the ideal operating line which satisfies minimum fuel consumption. In this context of view, there are many tries to achieve given object. However, the parameter in the internal combustion engines are variable and depend on the operating points. Therefore, it is necessary to cope with the uncertainties such that the optimal operating may be possible. From this point of view, this paper gives a controller design method and a robust stability condition for engine torque control which satisfies the given control performance and robust stability in the presence of physical parameter perturbation. Exactly, the present paper considers a robust stability of this 2DOF servosystem with nonlinear type uncertainty in the engine system, and a robust stability condition for the servosystem is introduced. This result guarantees that if the plant uncertainty is in the permissible set defined by the given condition then a gain tuning can be carried out to suppress the influence of the plant uncertainties.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.11
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• pp.1029-1037
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• 2010

If an internal combustion engine is operated by consolidated control, the minimum fuel consumption is achieved and the demanded objectives are satisfied. For this, it is necessary that the engine is operated on the ideal operating line which satisfies minimum fuel consumption. In this context of view, there are many tries to achieve given object. However, the parameters in the internal combustion engines are variable and depend on the operating points. Therefore, it is necessary to cope with the uncertainties such that the optimal operating may be possible. From this point of view, this paper gives a controller design method and a robust stability condition for engine torque control which satisfies the given control performance and robust stability in the presence of physical parameter perturbation. Exactly, in this paper, we consider the robust stability problem of this 2DOF servosystem with nonlinear type uncertainty in the engine system, and a robust stability condition for the servosystem is shown. This result guarantees that if the plant uncertainty is in the permissible set defined by the given condition, then a gain tuning can be carried out to suppress the influence of the plant uncertainties.

• Journal of Applied Reliability
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• v.18 no.2
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• pp.184-191
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• 2018

Purpose: The purpose of this study is to propose a method to calculate the optimal preventive maintenance cycle of radar used in the aviation weapon system of ROKAF. Methods: A hybrid model is used to estimate the optimal preventive maintenance cycle in a system that can perform condition based predictive maintenance (CBPM) through continuous diagnosis. The failure data of the radars operating in the military were used to calculate the reliability. Results: According to the research results, the reliability threshold of the radar began to decrease after 5 flights, and decreased rapidly after 12 flights. Since the second check, costs have continued to decline. Conclusion: A method is proposed to determine the cycle of optimal preventive maintenance of radar within operational budget through modeling results between reliability limit and cost for radar. The results can be used to determine the optimal preventive maintenance cycle and frequency of various avionics equipment.

• Journal of Biosystems Engineering
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• v.42 no.4
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• pp.242-250
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• 2017

Purpose: This study was conducted to determine the appropriate operating conditions through a factorial experiment for the secondary separating part of the self-propelled pepper harvester. Methods: An experimental setup that simulates the secondary separating part of the self-propelled pepper harvester was organized. Test samples were classified into three types according to the number of peppers on a stem, and 12 sets were prepared for each type. Among the operating conditions of the secondary separating part, the rotational speed of drum B (four levels), radial clearance between drums and cylindrical teeth (three levels), and speed ratio between the three drums (two levels) were set as the test factors, and tests were repeated three times for different levels of each factor. The appropriate operating conditions were determined by analyzing the separation ratio and damage ratio of the peppers collected through the secondary separating part. Results: The test factors changed the overall separation ratio and overall damage ratio in similar trends. In other words, the conditions that caused high overall separation ratios also exhibited high overall damage ratios. Owing to the high overall damage ratio in the condition with the highest overall separation ratio, the operating conditions should be selected considering both ratios. Conclusions: When the condition with more than 60% of overall separation ratio and less than 15% of overall damage ratio was considered as the appropriate operating condition, 70 rpm of the rotational speed of drum B, 5 mm of the radial clearance between drums and cylindrical teeth, and 7:3:5 for the speed ratio of the three drums A, B, and C should be applied for the secondary separating part used in this study. Supplementary studies will be required in the future to find optimal operating conditions through the actual field test under further divided test factors.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.825-829
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• 2005

This paper presents an approach for designing a fuzzy logic-based adaptive SVC damping In controller for damping low frequency power oscillations. Power systems are often subject to low Frequency electro-mechanical oscillations resulting from electrical disturbances. Generally, power system stabilizers are designed to provide damping against this kind of oscillations. Another means to achieve damping is to design supplementary damping controllers that are equipped with SVC. Various approaches are available for designing such controllers, many of which are based on the concepts of damping torque and others which treat the damping controller design as a generic control problem and apply various control theories on it. In our proposed approach, linear optimal controllers are designed and then a fuzzy logic tuning mechanism is constructed to generate a single control signal. The controller uses the system operating condition and a fuzzy logic signal tuner to blend the control signals generated by two linear controllers, which are designed using an optimal control method. First, we design damping controllers for the two extreme conditions; the control action for intermediate conditions is determined by the fuzzy logic tuner. The more the operating condition belongs to one of the two fuzzy sets, the stronger the contribution of the control signal from that set in the output signal. Simulation studies done on a one-machine infinite-bus and a four-machine two-area test system, show that the proposed fuzzy adaptive damping SVC controller effectively enhances the damping of low frequency oscillations.

• Journal of the Korea Organic Resources Recycling Association
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• v.21 no.4
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• pp.44-49
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• 2013

An establishment of dioxin-reduction operating skill for medium sized incineration facility is urgently needed in Korea with nearly 90% of medium sized incineration. Using lattice stoker incineration processing the capacity of 20 tons industrial general waste per day, similar properties of the household waste, dioxin-reduction is derived in optimum operating condition and parameters. As a result, CO haunting which is the minimization of frequency is found as the major parameter to minimize dioxin.