• Journal of Korean Foot and Ankle Society
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• v.13 no.1
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• pp.40-45
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• 2009

Purpose: End-stage ankle arthritis is frequently combined with ankle-hindfoot deformity or ankle instability and therefore additional surgical procedures are often required when performing total ankle arthroplasty. We report the short term clinical and radiographic results of the total ankle arthroplasty with/without the combined adjunctive surgical procedures. Materials and Methods: The study is based on the 17 ankles (16 patients) of end-stage ankle arthritis that were treated with $HINTEGRA^{(R)}$ Total ankle prosthesis (Newdeal, Lyons, France) total ankle arthroplasty (TAA) from 2004 to 2007 with at least 12 months follow-up. The combined adjunctive procedures as well as the VAS pain score, AOFAS score, radiographic measurements and patient satisfactions were evaluated. Results: Average follow-up period was 29 months (13${\sim}$55 months), and the age was average 62 years (39${\sim}$75 years) old. Among total of 17 ankles, varus deformity and lateral ankle instability were found in 4 cases and 3 cases respectively. Twenty additional procedures such as Achilles triple hemisection (9), calcaneal displacement osteotomy (4) and lateral ankle ligament reconstruction (3) were performed in adjunct to TAA in 13 ankles. VAS pain score improved from preoperative average 8.4 (7${\sim}$10) to 2.0 (0${\sim}$5) and the AOFAS functional score improved from 41.8 points (13${\sim}$71 points) to 90.6 (77${\sim}$100 points) at final follow-up. Ninety-four percent of the patients were satisfied with the surgery. Conclusion: We confirmed that many adjunctive combined surgical procedures are often necessary in addressing the end-stage ankle arthritis (74%) with total ankle arthroplasty. We also achieved quite good clinical and radiographic short term results, although the long term follow-up study with larger number of cases are needed in the future.

• Proceedings of the Korean Statistical Society Conference
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• 2005.11a
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• pp.13-17
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• 2005

In recent years, many people use R as a statistics system. R is frequently updated by many R project teams. We are interested in the method of multiple outlier detection and know that R is not supplied the method of multiple outlier detection. In this talk, we review these procedures for detecting multiple outliers and provide more efficient procedures combined with direct methods and indirect methods using R.

• The Korean Journal of Applied Statistics
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• v.1 no.2
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• pp.10-26
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• 1987

If the forecasts from different, sources are combined in some way, the resulting forecasts may be more accurate than any of the individual components. In this paper, the established procedures of combining forecasts are reviewed and the alternative procedures are suggested. By the results of empirical analysis from survey data, the method of combining forecasts using the restricted regression weights, the restricted robust regression weights, and mixed regression weights are robust. We can not find the most efficient combined forecasts in any case if we select the corresponding decision by preliminary analysis for the statistical properties of individual dorecasts, our results of combined forecast can became useful.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.1 no.1
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• pp.95-103
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• 2001

The purpose of Introducing a combined cycle with gas turbine in power plants is to reduce losses of energy, by effectively using exhaust gases from the gas turbine to produce additional electricity or process. The efficiency of a combined power plant with the gas turbine increases, exceeding 50%, while the efficiency of traditional steam turbine plants is approximately 35% to 40%. 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 neural network tuning of the 2-DOF PID controller with a combined 2-DOF parameter (NN-Tuning 2-DOF PID controller), for optimal control of the Gun-san gas turbine generating plant in Seoul, Korea. In order to attain optimal control, transfer function and operating data from start-up, running, and stop procedures of the Gun-san gas turbine have been acquired and a designed controller has been applied to this system. The results of the NN-Tuning 2-DOF PID are compared with the PID controller and the conventional 2-DOF PID controller tuned by the Ziegler-Nichols method through experimentation. The experimental results of the NN-Tuning 2-DOF PID controller represent a more satisfactory response than those of the previously-mentioned two controllers.

• Steel and Composite Structures
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• v.4 no.3
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• pp.189-209
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• 2004

The commonly used seismic design procedures to evaluate the maximum effect of both horizontal components of earthquakes, namely, the Square Root of the Sum of the Squares (SRSS) and the 30-percent (30%) combination rules, are re-evaluated. The maximum seismic responses of four three-dimensional moment resisting steel frames, in terms of the total base shear and the axial loads at interior, lateral and corner columns, are estimated as realistically as possible by simultaneously applying both horizontal components. Then, the abovementioned combination rules and others are evaluated. The numerical study indicates that both, the SRSS rule and the 30% combination method, may underestimate the combined effect. It is observed that the underestimation is more for the SRSS than for the 30% rule. In addition, the underestimation is more for inelastic analysis than for elastic analysis. The underestimation cannot be correlated with the height of the frames or the predominant period of the earthquakes. A basic probabilistic study is performed in order to estimate the accuracy of the 30% rule in the evaluation of the combined effect. Based on the results obtained in this study, it is concluded that the design requirements for the combined effect of the horizontal components, as outlined in some code-specified seismic design procedures, need to be modified. New combination ways are suggested.

• The Transactions of the Korean Institute of Power Electronics
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• v.8 no.4
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• pp.328-335
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• 2003

Test procedure for Electric Vehicle(EV) motor/controller has been developed. Most of existing standards mainly focus on minimum requirements for safe operation. However, detailed test procedures are not covered in the standard. In order to develop test items, methods and procedures which should be strictly applied to EV motor and controller, existing standards have been reviewed by the expert group in Korea. Based on their feedback, standard test procedure was proposed. Test procedure especially for combined motor and controller has been proposed. As a load lot the tested motor, M-G set, eddy current type engine dynamo and AC dynamo were used. Test procedures for the driving cycle test and regeneration test were proposed.

• Journal of Chest Surgery
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• v.9 no.2
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• pp.207-214
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• 1976

Operations for cardiac valvular disease has been progressed in various ways. Since 1949 when Lord Russel operated mitral stenosis by closed technique at Johns Hopkins Hospital then much progress has been achieved and that nowadays severely diseased cardiac valve has been replaced by prosthetic valve, which is almost ideal in hemodynamic aspect, but still it has many problems such as thromboembolism, destruction of red blood cell, pressure gradient, and disturbance of left ventricular function, so in case of delicate situations, valve replacement should be decided carefully. Besides prosthetic valve, there are some kinds of reconstructive procedures and these have been resulted in better prognosis than prosthetic valve replacement in selected cases. So, authors have reviewed 61 Cases of cardiac patients who have been operated reconstructive valvular surgery by cardiopulmonary bypass, at Yonsei University, from Jan. 1963 to Mar. 1976. Out of 61 cases, 9 patients were replaced by prosthetic valve and rest of the patients were operated upon in various reconstructive procedures such as commissurotomy, valvotomy, valvuloplasty, and annuloplasty. Twenty cases of congenital heart diseases with valvular lesion, which had been operated for valvular lesion were also included in this statistics. Out of 9 cases of prosthetic valvular replacement five cases of prosthetic valvular replacement was done combined with other reconstructive procedures after attempted valvuloplasty. Comparative prognosis of both procedures are somewhat variable by reporters, average 19% of mortality after reconstructive surgery and 38% of mortality after prosthetic valve replacement in long term results. Most common cause of death in postoperative period was low output syndrome in both cases. It seems that good preoperative evaluation and proper reconstructive surgery will afford good prognosis in selected cardiac valvular diseased patient.

• Communications for Statistical Applications and Methods
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• v.12 no.3
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• pp.713-727
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• 2005

Among different regression approaches, nonparametric procedures perform well under different conditions. In practice it is very hard to identify which is the best procedure for the data at hand, thus model combination is of practical importance. In this paper, we focus on one dimensional regression with fixed design. Polynomial regression, local regression, and smoothing spline are considered. The data are split into two parts, one part is used for estimation and the other part is used for prediction. Prediction performances are used to assign weights to different regression procedures. Simulation results show that the combined estimator performs better or similarly compared with the estimator chosen by cross validation. The combined estimator generates a similar risk to the best candidate procedure for the data.

• Journal of the Korea Safety Management & Science
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• v.12 no.1
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• pp.199-205
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• 2010

The research proposes the three-factor random measurement models for estimating the precision about operator, part, tool, and various measurement environments. The combined model with crossed and nested factors is developed to analyze the approximate F test by degrees of freedom given by Satterthwaite and point estimation of precisions from expected mean square. The model developed in this paper can be extended to the three useful models according to the type of nested designs. The study also provides the three-step procedures to evaluate the measurement precisions using three indexes such as SNR(Signal-To-Noise Ratio), R&R TR(Reproducibility&Repeatability-To-Total Precision Ratio), and PTR(Precision-To-Tolerance Ratio), The procedures include the identification of resolution, the improvement of R&R reduction, and the evaluation of precision effect.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.6 no.3
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• pp.11-20
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• 1986

The purpose of this study is to devise an efficient and economic solution algorithm for the nonlinear finite element equations. First, procedures and characteristics of the solution methods of ordinary nonlinear equations are critically reviewed and discussed. Based on the discussion, some promising nonlinear finite element analysis procedures are presented as an algorithmic form. Finally, a conceptually combined algorithm for a solution of nonlinear finite element equations is proposed and analyzed, in which the computational effort is minimized and numerical difficulties can be avoided.