• Clinics in Shoulder and Elbow
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• v.10 no.2
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• pp.183-189
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• 2007

Introduction: While uncommon, humeral head osteonecrosis is an indication for arthroplasty when the humeral head collapse is advanced. The current authors report the short-term clinical results of 7 hemiarthroplasties to treat humeral head osteonecrosis. Materials and Methods: This study focused on 7 reconstructed shoulders of 5 patients whose humeral head osteonecrosis was treated with hemiarthroplasty. The postulated causes were alcohol-induced (4 cases) and steroidinduced (3 cases). The minimum follow-up was 12 months. This study compared the preoperative and postoperative shoulder pain, range of motion, and ASES scores. The postoperative patient satisfaction was assessed. Results: The level of pain during exercise was reduced from a preoperative average of 7.6 to a postoperative average of 1.9. The range of motion, in terms of forward flexion, abduction, and external rotation, improved from preoperative averages of $105.7^{\circ}$, $80^{\circ}$, and $22.1^{\circ}$ to postoperative averages of $146.6^{\circ}$, $139.3^{\circ}$, and $44.3^{\circ}$, respectively. The ASES scores increased from a preoperative mean of 39.0 to a postoperative mean of 84.1. The patients' ratings of the outcomes were excellent (5 cases) and good (2 cases). Conclusions: These short-term results indicate that hemiarthroplasty is a reliable treatment method for humeral head osteonecrosis improving shoulder pain, range of motion, and patient satisfaction.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.11
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• pp.1138-1144
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• 2011

This article deals with the problem of fault detection of a spacecraft's actuators. The authors introduce an extended unknown input observer for nonlinear systems. This is an extended form of unknown input observers which are used for linear systems. Since faults are not available, those are considered as unknown inputs. Unknown input observers can estimate states without full information of inputs if some conditions are satisfied. The authors suggest a continuous-time extended UIO (eUIO) and prove the convergence of state estimation errors. Since the dynamic equation of a spacecraft is nonlinear, an extended UIO can be applied. Three eUIOs are designed to monitor three reaction wheels. The moving averages of each eUIO's residuals are selected for decision logic. The proposed method is verified by numerical simulations.

• Bulletin of the Korean Chemical Society
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• v.27 no.10
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• pp.1659-1663
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• 2006

A many-body master equation is constructed by incorporating stochastic terms responsible for chemical reactions into the many-body Smoluchowski equation. Two forms of Langevin-type of memory equations describing the time evolution of dynamical variables under the influence of time-independent perturbation with an arbitrary intensity are derived. One form is convenient in obtaining the dynamics approaching the steady-state attained by the perturbation and the other in describing the fluctuation dynamics at the steady-state and consequently in obtaining the linear response of the system at the steady-state to time-dependent perturbation. In both cases, the kinetics of statistical averages of variables is found to be obtained by analyzing the dynamics of time-correlation functions of the variables.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.694-696
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• 2003

The KOMPSAT/OSMI remote sending data of 800 km swath are collected by whisk broom method employing 96 charge coupled devices (CCDs). The stripping noise in the OSMI imageries, which arise mainly due to the non-uniform sensitivities of 96 CCDs, are the major hindrance for oceanographic applications of the OSMI data. The OSMI images are corrected by 'Ensemble Smoothness' method which is based on an assumption that the series of the averages and variances of digital numbers in each line should vary smoothly. The data of each line are corrected by linear regression model of which coefficients are obtained by Ensemble Smoothness method. Our algorithm can be applied not only to OSMI data but also for other remote sensing date collected by whisk broom or push broom.

• Journal of Ocean Engineering and Technology
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• v.25 no.3
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• pp.85-89
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• 2011

This study aimed to develop a wind turbine system for the domestic wind environments. The Taguchi method was applied to obtain the optimal design for a wind turbine with a wind-shield. The design parameters were defined to look for the shape of the wind turbine. Optimal parameters were determined on the basis of the analyzed level averages of the characteristics. According to the test results to which the optimal parameters were applied, the rpm improved. It was also found that a windshield 3/4 the size contributes to improving the efficiency of existing turbines.

• Journal of Navigation and Port Research
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• v.35 no.4
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• pp.317-321
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• 2011

In this paper, a foggy-degraded image restoration technique with a physics-based degradation model is proposed for the measurement system. When the degradation model is used for the image restoration, its parameters and a distance from the spreader to the camera have to be previously known. In the proposed image restoration technique, the parameters are estimated from variances and averages of intensities on two foggy-degraded landmark images taken at different distances. Foggy-degraded images can be restored with the estimated parameters and the distance measured by the measurement system. On the basis of the experimental results, the performance of the proposed foggy-degraded image restoration technique was verified.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2001.10a
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• pp.501-504
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• 2001

The prototype biofilter was constructed in Suwon campus of Seoul National University and monitored for temperature and treatment efficiencies during a two-year programme. During the winter, daily influent wastewater temperature averages $7.7C^{\circ}$; without heating in 2000 experiment, the treatment efficiencies for BOD and SS droped down to 88.7% and 68.4%, respectively. However, as increased the influent wastewater by installting a heater tank before the biofilter tank in 2001 at the same period ($Feb.\;9{\sim}Mrach\;30$) of 2000 experiment, average daily influent temperature which was $7.2C^{\circ}$ increased to over $18.2C^{\circ}$. As a result, effluent quality remains excellent through the winter and even the post winter with BOD and SS values close to less than 10 mg/L. Nitrification follows temperature patterns. However, there was no improvement of treatment efficiency in total nitrogen (T-N) was observed by increasing temperature.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2001.09a
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• pp.88-91
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• 2001

The purpose of this study is to localize the recharge rate into the national scale, calculated by use of the groundwater level from the 123 monitoring stations. The soil type, land use type, and bedrocks are selected for the influential factors over recharge rate. The main hypothesis is that the recharge rate can be expressed by the sum of the weighted averages of recharge rates of each factors. The optimized weights of soil type, land-use time and bedrocks from 119 stations are 0.80, 0.18 and 0.02 respectively. So this study offers that localization is available from the recharge rates calculated by groundwater level monitoring results.

• International Journal of Quality Innovation
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• v.3 no.2
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• pp.57-73
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• 2002

Recent interests in total quality management (TQM) and business excellence (BE) had been fuelled with a range of national and regional awards. These awards are being increasingly used by organisations as part of the business improvement process and strategic benchmarking. This paper reviews the concepts and approaches of performance measurement (PM) and discusses the integration of PM with the TQM and BE philosophies. A TQM-BE-PM framework with a set of self-assessment checklists was developed. In order to complement the literature base with empirical evidence, an industry survey was conducted and a trial implementation of the framework was carried out in a leading manufacturing firm in Hong Kong. The self-assessment performance data of the fm was evaluated and then benchmarked with the industry averages obtained from the survey. This paper presents the empirical findings and discusses the applicability of the framework in measuring and benchmarking organisational performance toward continual improvement.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.26 no.3
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• pp.138-155
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• 2022

To solve the initial value problem we present a new single-step implicit method based on the Euler method. We prove that the proposed method has convergence order 2. In practice, numerical results of the proposed method for some selected examples show an error tendency similar to the second-order Taylor method. It can also be found that this method is useful for stiff initial value problems, even when a small number of nodes are used. In addition, we extend the proposed method by using weighted averages with a parameter and show that its convergence order becomes 2 for the parameter near $\frac{1}{2}$. Moreover, it can be seen that the extended method with properly selected values of the parameter improves the approximation error more significantly.