• The Korea Journal of Herbology
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• v.25 no.1
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• pp.45-54
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• 2010

Objectives : The purpose of this study is to determine the impurity tolerance of Zanthoxylum Peel. Methods : Compare with medicinal Herb Books and the Pharmacopoeia of 6 nations. Results : Current Pharmacopoeia show different Zanthoxylum Peel's Purity, such as 2.0% of seeds and fruit stalk, etc. in North Korea, 2% of seeds in Vietnam, totally 3% in China. On the other hand, Korea and Japan set the total number 26.0% including the specific numbers such as 20.0% of seeds, 5.0% of fruit stalk, 1.0% of the other foreign matter. This Zanthoxylum Peel's Purity, 26.0%, is too high compared to that of other medical matters specified by The Korean Pharmacopoeia Ninth Edition. When The Japanese Pharmacopoeia Sixth Edition firstly set the Zanthoxylum Peel's Purity, the herbal name was Fructus. However, since the part for medical usage in origin is well-ripen pericarp, not seed, the permissible level, 30.0%, is supposed to be simple error range, 3.0%. Conclusions : As a result, I think bills concerning the Zanthoxylum Peel's Purity should be revised to the total number 3.0% or specifically set the level 2.0% of seeds, 1.0% of fruit stalk, twig and so on.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.6
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• pp.453-462
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• 2016

This paper proposes a torque control method for surface mounted permanent magnetic synchronous motor (PMSM) driven by a 2-level voltage source driven inverter, which has fast torque response and small torque ripple. The proposed torque control method follows the finite control set model predictive control (FCS-MPC) strategy. A reference state is derived at each time step for the given time varying torque reference and the cost index is defined so that the tracking error for this reference state should be penalized. The choice of an optimal output voltage vector is made first from the 6 possible active voltage vectors of the 2-level voltage source inverter. Then a modulation factor for the chosen optimal voltage vector is obtained so that the torque ripple can be reduced further. It is shown that the proposed FCS-MPC control method yields fast torque tracking response and small torque ripple through simulation and experiments.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.4
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• pp.967-975
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• 2010

Image segmentation is one of the first steps leading to image analysis and interpretation, which is to distinguish objects from background. However, the active contour model can't exactly extract the desired objects because the phase only is 2. In this paper, we propose the method which can find the desired contours by composing the initial curve near the objects which have intensities of special range. The initial curve is calculated by the histogram equalization, the Gaussian equalization, and the threshold. The proposed method reduce the calculation speed and exactly detect the wanted objects because the initial curve set near by interested area. The proposed method also shows more efficient than the active contour model in the results applied the CT and MR images.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.12
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• pp.2189-2196
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• 2016

This paper proposes a new finite control set-model predictive control (FCS-MPC) method for induction motors. In the method, the reference state that satisfies the given torque and rotor flux requirements is derived. Cost indices for the FCS-MPC are defined using the state tracking error, and a linear matrix inequality is formulated to obtain a proper weighting matrix for the state tracking error. The on-line procedure of the proposed FCS-MPC comprises of two steps: select the output voltage vector of the two level inverter minimizing the cost index and compute the optimal modulation factor of the minimizing output voltage vector in order to reduce the state tracking error and torque ripple. The steady state tracking error is removed by using an integrator to adjust the reference state. The simulation and experimental results demonstrated that the proposed FCS-MPC shows good torque, rotor flux control performances at different rotating speeds.

• Journal of Power Electronics
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• v.19 no.4
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• pp.989-999
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• 2019

This paper proposes a fault-tolerant control strategy with finite control set model predictive control (FCS-MPC) based on hierarchical optimization for five-level H-bridge neutral-point-clamped (5L-HNPC) inverter-fed induction motor drives. Fault-tolerant operation is analyzed, and the fault-tolerant control algorithm is improved. Adopting FCS-MPC based on hierarchical optimization, where the voltage is used as the controlled objective, called model predictive voltage control (MPVC), the postfault controller is simplified as a two layer control. The first layer is the voltage jump limit, and the second layer is the voltage following control, which adopts the optimal control strategy to ensure the current following performance and uniqueness of the optimal solution. Finally, simulation and experimental results verify that 5L-HNPC inverter-fed induction motor drives have strong fault tolerant capability and that the FCS-MPVC based on hierarchical optimization is feasible.

• Journal of the military operations research society of Korea
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• v.29 no.2
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• pp.13-25
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• 2003

The lack of consideration for statistical properties in Taguchi's three­level linear graphs is rectified. We propose a new set of linear graphs for the three­level orthogonal arrays according to the maximum resolution criterion. In the presence of two­factor interactions however, the serious bias of all the estimated effects as well as the estimated variance shows that these designs should not be employed. The various alternative designs are discussed.

• Journal of the Korean Mathematical Society
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• v.34 no.4
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• pp.927-947
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• 1997

A practical estimation method for groundwater level elevations is introduced. Using geostatistical techniques with drift, averaging process and ratio, experimental variograms show significant improved coorelation compared with those from conventional techniques. The estimation method is applied to a field experimental data set.

• Tunnel and Underground Space
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• v.7 no.1
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• pp.51-57
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• 1997

This study provides the results of two different blasting methods applied at the H Telcon construction site in Yeon-dong, Cheju Island. One is the traditional blasting method without bottom-hole stemming and the other with bottom-hole stemming using the materials such as sand, polystyrene and sawdust in 5~10 cm lengths. The effect of these materials on vibration level was studied. Assuming that safety criterion of vibration level be 0.5cm/set, 95% confidence limit line of measured data shows that maximum charge weight per delay could be increased in the following order; traditional methed, polystyrene stemming, sand stemming, sawdust stemming.

• Journal of the Korean Statistical Society
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• v.25 no.4
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• pp.489-497
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• 1996

Lower bounds for the full level probabilities are derived under order restrictions in weights. Discussions are made on typical isotonic cones such as linear order, simple tree order, and unimodal order cones. We also discuss applications of these results for constructing conditional likelihood ratio tests for ordered hypotheses in a contingency table. A real data set on torus mandibularis will be analyzed for illustrating the testing procedure.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2003.10a
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• pp.531-534
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• 2003

A model using a nonlinear programming technique was applied for allocating the optimal water depending on storage level changes of the Sumjin dam. The objective function of optimization model was set up to maintain the storage at target level, to satisfy the water demand, and to maximize the hydropower production. In this way, the water allocation as to target level and instream flow was optimized and compared with historical operational data.