• The Korean Journal of Applied Statistics
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• v.27 no.5
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• pp.833-842
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• 2014

Non-inferiority trials indicate whether the effect of an experimental treatment is not worse than an active control. Chen et al. (2006) and Kang (2010) proposed a test method for non-inferiority trials using confidence intervals. In this paper, we suggest a new nonparametric method using a confidence interval based on Wilcoxon rank-sum test and Hodges-Lehmann estimator of active control. A Monte-Carlo simulation study compares the type I error and the power of the proposed method with previous methods.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.29B no.11
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• pp.73-84
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• 1992

In this paper, an algorithm for recovering the 3-D shape from a single shaded image is proposed. In the proposed algorithm, by using the relation between the height and surface gradient (p, q), a set of linear equations is derived from the linearized reflectance function. Then the 3-D surface is recovered by employing the conjugate gradient technique. In order to improve the convergence speed of the solution, we also employ the hierarchical basis function and multiresolution images in the algorithm. A method for determining the regularization parameter, which is determined by trial and error in the conventional approach, is also introduced. In addition, the proposed algorithm attempts to recover the 3-D surface without requiring the boundary conditions, making it suitable for a real-time implementation. Simulation results for real image as well as synthetic image are provided to demonstrate the performance of the proposed algorithm.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2002.10a
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• pp.361-364
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• 2002

The WASP model was applied to Bokha stream with 8.4km of its main stem located in Ichon-gun, Kyonggi province in Korea. The stream was divided into 26 segments with each of 400m length, and 5 segments were embraced boundaries of its tributaries. The parameters of the model were calibrated by the trial and error method to minimize differences between observed and simulated concentration of water quality constituents. The correlation coefficients for DO, $NO_3-N,\;PO_4-P$ and organic P showed high values providing the ability of simulation. The correlation coefficients for BOD and $NH_3-N$ showed low values in both calibration and verification test.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.37 no.11
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• pp.826-833
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• 1988

In this paper we studied the control of overload which could bring the degradation of performance and threaten the stability of the electronic switching system. In order to get the essential requirement for overload control algorithm, we tried to extract the characteristics of commonly used algorithms by means of simulating overload control alogrithms in numerical stored program control switching model. As the result, we could find that the overload control algorithm which monitored the CPU occupancy had the best call complete rate and good response characteristecs and the algorithm using the offered load as a system state variable had a good grade of service which was represented by a short dial tone delay and 3rd quartile of deal tone delay. however, these control algorithms have no generality and need to get the control parameters by the trial-and-error method. We suggested the guidelines on the design of the overload control algorithm.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.7 no.3
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• pp.227-232
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• 1995

A new evaluation procedure for calculating the Jacobian elliptic parameter is presented. This procedure is useful in calculating the trajectory for cnoidal wave generation. Upon specification of water depth, the wave height and either the wave period or the wavelength, the presented algorithm uses the Newton-Raphson method and the arithmetic and geometric-mean scales to calculate the profile directly, without trial and error procedures or look-up in tables. It is shown that the algorithm provides equally accurate result as the ad hoc methods previously used.

• Journal of the Korean Society for Precision Engineering
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• v.8 no.3
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• pp.64-72
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• 1991

This paper deals with the state estimator and controller. All state variables' feedback in the system were used to improve electro hydraulic servo sysem were used to improve electro hydraulic servo system's responese charact- eristics. Many gains of the state variables'and estimator's are produced by the algebraic Riccati equation, and every state variables'optimal gain and estimator gain is selected by trial and error method. For the designed estimator performance's examination, this paper simulate the time response for the step input, the reduced velocity output in subjected to load torque, and the time response for the step input in changing the inertiamoment.

• Proceeding of EDISON Challenge
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• 2017.03a
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• pp.540-546
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• 2017

Bipedal robots tend to have greater mobility than conventional treaded or wheeled robots yet they are commonly complicated by instabilities in balance. This paper presents a bipedal robot based upon Jansen's locomotive mechanism which addresses these challenges in stability and efficiency. In order to achieve a functioning robot, we considered a multitude of variables in its motion including, the Ground Score, Drag Score, step size, foot lift, stride, and instantaneous speed of the Jansen mechanism. Matlab and Jansen Opt solver were used to optimize the legs of the robot. A trial and error experimental method was used to determine the best combination of link lengths, and m.Sketch was used to model our results. Finally, we drew the entirety of the robot's figure by using the Edison design.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2006.05a
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• pp.89-92
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• 2006

To investigate the properties of high flowing and high strength concrete with crushed sand and fly ash for CFT structure, many batches were performed by a trial-error method. In the experiment W/B was set up three levels as 0.25, 0.30 and 0.35. Also the variables of the experiment were a substitution ratio of fly ash, a blend ratio of crushed sand and the ages of specimens(3, 7, 28 days). The results of this study are summarized as the follows; 1) The effect a substitution ratio of fly ash on the compressive strength was not consistent with age. For twenty-eight day compressive strength, the best result was come out when cement was substituted by 10% of fly ash. 2) The decrease of the water binder ratio, the increase of compressive strength and elastic modulus. Also the relationship is very similar to the case of a normal concrete

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.3 no.1
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• pp.78-86
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• 2003

Multivariable control system exist widely in many types of systems such as chemical processes, biomedical processes, and the main steam temperature control system of the thermal power plant. Up to the present time, Pill Controllers have been used to operate these systems. However, it is very difficult to achieve an optimal PID gain with no experience, because of the interaction between loops and gain of the Pill controller has to be manually tuned by trial and error. This paper suggests a tuning method of the Pill Controller for the multivariable power plant using an immune algorithm, through computer simulation. Tuning results by immune algorithms based neural network are compared with the results of genetic algorithm.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2129-2131
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• 2001

Induction motor has been using for industrial field. Up to the present time, the PID controller has been used to operate this system. However, it is very difficult to achieve an optimal PID gain without any experience, since the gain of the PID controller has to be manually tuned by trial and error procedures. This paper focuses on the fuzzy control for optimal control of the induction motor in plant. In order to attain optimal control, flux, torque and speed controller has been used and an fuzzy logic based controller has been applied to this system. The results of the fuzzy are compared with the PID controller tuned by the Ziegler-Nickels method, through various simulation based on the various disturbance and step response. The simulation results of the fuzzy control represent a more satisfactory response than those of the conventional controllers.