• Korean Journal of Applied Biomechanics
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• v.22 no.2
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• pp.243-251
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• 2012

The purpose of this study was to develop an impact force measurement device in order to facilitate the acquisition of quantitative data for the analysis of various sporting events. The device was designed to include cylindrical aluminum supports of 220 mm diameter, which allows mounting and dismounting of the device on walls and frames. In addition, a hard sponge for impact absorption, as well as 4 springs, were attached to the plate. Both were attached to prevent psychological variables and injuries. When a subject applies force on the device, accurate data about the maximum repulsive force is acquired in real time, with a lag of only 0.001 s. The device was calibrated in four steps: (1) increase, (2) increase, (3) increase-decrease, and (4) increase-decrease. The maximum relative expanded uncertainty was 0.166%, indicating that the impact force measurement was sufficiently reliable. The proposed device can be applied to various sporting situations and is expected to be useful for studying kinetics.

• Korean Management Science Review
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• v.33 no.4
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• pp.77-89
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• 2016

Due to recent proliferation of the mobile shopping channels, customers increasingly tend to purchase using online channel while experiencing physical products in offline shops. This phenomenon requires traditional offline retailers to consider integrating online channels. In this study, we propose strategic options for the traditional offline retailers regarding the online channel integration, and provide corresponding decision models to maximize the expected profits. We also investigate how the strategic options vary with the product characteristics, by categorizing the products based on inventory cost, demand uncertainty, and fitness to the online channels. By analyzing numerical examples we illustrate how the best online channel integration strategy should be differentiated depending on the product categories.

• Journal of Electrical Engineering and Technology
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• v.3 no.1
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• pp.135-142
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• 2008

This paper deals with the design of a robust PI controller for a vehicle suspension system. A method, which is related to computation of all stabilizing PI controllers, is applied to the vehicle suspension system in order to obtain optimum control between passenger comfort and driving performance. The PI controller parameters are calculated by plotting the stability boundary locus in the $(k_p,\;k_i)$-plane and illustrative results are presented. In reality, like all physical systems, the vehicle suspension system parameters contain uncertainty. Thus, the proposed method is also used to compute all the parameters of a PI controller that stabilize a vehicle suspension system with uncertain parameters.

• Atmosphere
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• v.20 no.1
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• pp.49-61
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• 2010

Atmospheric aerosols play a crucial role for changing climate, resulting in a wide range of uncertainty for future climate prediction. In this paper we review current international research status and trend of climate-related aerosol science. There have been carried out a number of campaigns (including ACE-Asia, TRACE-P, ABC, and so on) and special experiments with some modeling studies over Korea, East Asia, and the Northwestern Pacific to characterize the various properties (physical, chemical, optical, and radiative) of Asian aerosols and evaluate their climate forcing impacts. But some parts of the aerosol research may need to be improved, advanced, or newly launched. Especially, a chemical transport model (CTM) embedded by a general circulation model (GCM) should be developed by the national scientific community with a high research priority, actively collaborating with international community in order to estimate direct and indirect global radiative forcing due to anthropogenic and natural aerosols.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.11
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• pp.968-973
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• 2000

Fault diagnosis plays an important role in the performance and safe operation of many modern engineering plants. This paper investigates the problem of fault detection using neural networks in dynamic systems. A general framework for constructing a nonlinear fault detection scheme for nonlinear dynamic systems containing modeling uncertaintly is proposed. The main idea behind the proposed approach is to monitor the physical system with an off -line learning neural network and then to approximate the upper and lower thresholds of acceleration of the nominal system with the model-based threshold(ThMB) method, The performance of the proposed fault detection scheme is investigated through simulations of a pendulum with uncertainty.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.337-338
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• 2009

Use of the recycled fine aggregate as a material of structural concrete is not easy currently because there are some problems, such as of quality control and the uncertainty of chemical and physical property. Thus, the results indicate that it is possible to produce high quality recycled fine aggregate for structure by microwave heating technology, friction and abrasion action.

• Proceedings of the KIEE Conference
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• 1992.07a
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• pp.347-350
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• 1992

In this note, we propose a method for designing a robot controller which can suppress the effects of both the model uncertainty and noisy velocity measurements. The controller is an output feedback compensator of which the constant gains are given in terms of a Riccati equation and a Lyapunov equation. The controller guarantees not only uniform boundedness but uniform ultimate boundedness. The stability result is local but the region can be arbitrarily enlarged at the expense of large control gain. The control law needs neither the exact knowledge of the physical robot parameters nor clean velocity measurements.

• Journal of the Optical Society of Korea
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• v.13 no.2
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• pp.201-205
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• 2009

We investigated the optimum adhesive thickness for athermalizing an elastomeric lens mount in our space optics application. Theoretical results were compared with finite element solutions using two different models; discrete circular pads and discrete circular pads with columns filling the insertion holes reflecting the reality. A noticeable difference between their optimal thicknesses was observed, and physical interpretation revealed the uncertainty of prevailing athermal equations. A pilot sample was made to check our results and thermo-optical stress was assessed using an interferometer after isothermal load. This study presented insight into preliminary design guidance in elastomeric lens mounting.

• Journal of Korean Academy of Nursing Administration
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• v.19 no.2
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• pp.227-238
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• 2013

Purpose: The purpose of this study was to explore the lived experiences of new graduate nurses in personal life and in clinical setting during their first year. Methods: Eleven new graduate nurses were interviewed and the data were analyzed using the Giorgi's phenomenological method. Results: The main results of this research were negative experiences such as poor nursing skills, inability to enjoy personal life, physical exhaustion and health problems, and uncertainty of nursing values. On the other hand, there were some positive aspects on their minds: adjustmental/developmental needs, sense of responsibility, receptive capability, and proficiency with their work. They gradually found themselves being endured and changing to adapt. Conclusion: Transition from students to staff nurses is a very stressful experience for new graduate nurses. It may negatively affect their personal lives as well. However they tried to keep themselves positive to overcome their difficulties. It is necessary for them to be given time, a systematic program, and a supportive environment to adapt.

• The Korean Journal of Rehabilitation Nursing
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• v.6 no.1
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• pp.61-69
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• 2003

The purpose of this phenomenological study was to understand and describe the essence and the structure of lived experience of liver transplant recipient. Five individual interviews were conducted to gather data regarding their subjective experiences. About 130 significant statements were extracted and these were clusterd into 9 themes. End stage liver disease patients chose their last treatment - liver transplantation. After liver transplantation, recipients experience vague anxiety and uneaseness related to much information and life style change that they had to accept. And they feared to lose their health again. But they felt free from medication and restriction of food. And they satisfied with regaining their physical status. Most of the recipients also had financial difficulties and social restrictions. And they experience uncertainty about their future. But they restored their previous social life. And they experience psychological wellbeing and hope. The results of this study might help nurses who work with liver transplant recipient in establishing and implementing an effective nursing intervention by understanding their lived experience.