• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.327-330
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• 1996

It is well known that the controller output limits have a signifiant effect on the closed loop system performance. Considering the input constraints in GPCF, an effective selection method of the control weighting(.gamma.) is proposed to reduce the amplitude and the rate of control signals so that control signals lie within the limits. It is based on the relation between control weighting(.gamma.) and optimal solution of the unconstrained GPCF. The GPCFIC algorithm chooses an .gamma. at each sampling time so that all unconstrained GPCF output over the control horizon satisfy the rate and the amplitude constraints. In order to evaluate the performance of the GPCFIC, the computer simulations have been done for level control of PWR steam generator in low power operation and shown satisfactory results.

• 산업경영시스템학회지
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• 제25권2호
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• pp.50-56
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• 2002

In this study, we establish bootstrap control limits for EWMA chart by applying the bootstrap method, called resampling, which could not demand assumptions about pre-distribution when the process is skewed and/or the normality assumption is doubt. The results obtained in this study are summarized as follows : bootstrap EWMA control chart is developed for applying bootstrap method to EWMA chart, which is more sensitive to small shifts of process. With the purpose of eliminating a skewness of the resampling distribution, the bootstrap control limits are established by using a modified residual, and its performance is analyzed by ARL. It is shown that the bootstrap EWMA control chart developed in this study includes the properties of standard EWMA control chart that is sensitive to a small shift, and detects process in out of control more quickly than standard EWMA chart.

• 한국정밀공학회지
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• 제15권12호
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• pp.180-187
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• 1998

The stability and theoretical performance limits of the feedback controlled force reflecting haptic manipulator have been discussed. All the virtual environment which interact physically with the haptic system have its own stable performance limit. Three different realization of the interfaces have been compared using the driving point admittance. The haptic system which is separated from the human hand or finger is superior to its stable interaction provided that there is a means to apply a direct damping between the haptic manipulator and the human finger Electro-magnetic force is used for its digital implementation of the simple separated type haptic device. The stable limits of a virtual wall is calculated and experimental results show that there is performance limits in this implementation.

• The Journal of Korean Physical Therapy
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• 제19권6호
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• pp.37-41
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• 2007

Purpose: Hemiplegic patients usually present with difficulties in maintaining their balance. Balance retraining is a major component of a rehabilitation program for patients with neurological impairments. This study compared the effects of prorpioceptive exercise and visual feedback program on the limits of stability (LOS) in chronic hemiplegia patients. Methods: Thirty subjects (mean age $57.0{\pm}9.8$) were recruited. The subjects were divided into a proprioceptive group and a visual group. The subjects for the proprioceptive group participated in the proprioceptive exercise program for 4 weeks, and the visual group were treated with visual feedback training using a Balance Master. Results: At the 4 week follow-up test, the LOS in the proprioceptive group improved significantly in all directions (p<0.05). However, improvement was only observed in the forward direction in the visual feedback group. Therefore, the proprioceptive control approach improves the LOS in chronic hemiplegia patients. Conclusion: These results suggest that compared with physical therapy alone using a proprioceptive control approach to hemiplegia, there was no additional benefit of visual feedback training, such as Balance Master, when administrated in combination with other physical therapy interventions.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1997년도 춘계학술대회논문집; 경주코오롱호텔; 22-23 May 1997
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• pp.376-387
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• 1997

One of the main objectives of noise control act is to define and ensure application and respect of noise exposure limits. Most European countries have prepared a legal framework for noise limits either by national laws, ordinances or municipal by-laws. This paper presents the current European standards.

• 대한전기학회논문지
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• 제36권9호
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• pp.609-615
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• 1987

The optimal operation of power system is developed by alternately using real power dispatch and reactive power dispatch problem. The real power system scheduling process is formulated as an optimization problem with linear inequality constraints. A.C. loadflow method is used for the problem solution and line losses are considered. The constraints under consideration are generator power limits, load scehdling limits and line capacity limits. In solving the objective function the Dual Relaxation method is adopted. Tests indicate that the method is practical for real time application. The reactive power control problem uses the Dual Simplex Relaxation method as in the real scheduling case. Insted of minimizing the cost of power system, the objective is selected as to determine the highest possible voltage schedule. The constraints under consideration are the voltage limits at each node and the possibilities of supply or absobtion of reactive energy by generator units and the compensation facilities. Tests indicate that the method is practical for real time applications. The overall optimization methods developed in this paper proved to obtained fine results in minimizing object function compared with the method without using voltage control. And the overall voltage profiles were also improved.

• Communications for Statistical Applications and Methods
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• 제14권2호
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• pp.365-376
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• 2007

This research considers to propose the control charts using median for the location parameter. In order to decide the control limits, we apply several bootstrap methods through the approach obtaining the confidence interval except the standard bootstrap method. Then we illustrate our procedure using an example and compare the performance among the various bootstrap methods by obtaining the length between control limits through the simulation study. The standard bootstrap may be apt to yield shortest length while the bootstrap-t method, the longest one. Finally we comment briefly about some specific features as concluding remarks.

• Journal of Mechanical Science and Technology
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• 제16권1호
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• pp.60-74
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• 2002

In this study, normal, log-normal, triangular, uniform. Weibull, Erlang and unit beta probability density functions are tried to represent the behaviour of frequency distributions of workpiece dimensions collected from various manufacturing firms. Among the distribution functions, the unit beta distribution function is found to be the best fit using the chi-square test of fit. An attempt is made for the adoption of the unit beta model to x-bar charts of quality control in manufacturing. In this direction, upper and lower control limits (UCL and LCL) of x-bar control charts of dimension measurements are estimated for the beta model, and the observed differences between the beta and normal model control limits are discussed for the measurement sets.

• 대한기계학회논문집
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• 제11권1호
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• pp.145-153
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• 1987

본 논문에서는 예혼합동축분류화염에 있어서 재순환역 안으로의 기체(공기, 연료, 혼합기) 주입과 2차공기의 족회가 화염안정성, 화염형상 및 재순환역에 미치는 영향을 명확히 하였다.

• 한국산업보건학회지
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• 제24권2호
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• pp.103-112
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• 2014

Objectives: The present system of occupational safety and health law gives priority to traditional command and control regulations. However, this may give rise to problems such as the delay of standard-setting and shortages of human resources. The aim of this study is to examine the usability of private standards in occupational safety and health systems. Materials: After the limits of occupational safety and health law were examined, an application plan for private norms (EN, as enforced in the EU) and occupational safety and health management systems (OSHMS) was investigated. Results: The utilization of private norms and OSHMS may address the limits of the current legal system. In particular, OSHMS is known internationally as a measure for achieving improvements in overall occupational safety and health performance. As a result, occupational safety and health law and private norms/OSHMS are complementary to one another. Conclusions: Even though the utilization of private standards may give rise to legal questions, such standards as complementary measures to traditional command and control regulations need to be utilized progressively in occupational safety and health systems.