• Journal of Electrical Engineering and Technology
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• v.11 no.2
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• pp.347-352
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• 2016

This paper investigates the application, design and implementation of unscented Kalman filter observer using the various scaling parameters for the sensorless speed control of a permanent magnet synchronous motor. The principles of unscented transformation and unscented Kalman filter are examined and their applications are explained. Typically the mapping transformation process is divided into two types, namely the basic unscented transformation and the general unscented transformation by virtue of the scaling parameter value. And resultantly, the number of sampling points, weights, code configuration and computation time are different. But there is no little information on the scaling parameter value or how this value influences the system performance. To analyze the unscented transformation with the various scaling parameters in this study, the experimental results under a wide range of operation condition have been demonstrated.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.10
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• pp.2446-2456
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• 1993

By virtue of progress of computer science, CAD/CAM technology has been developed greatly in each area. But the problems in the integration of CAD/CAM are not yet solved completely. The reason is that the exchange of data between CAD and CAM is difficult because the domains of design and manufacturing are different in nature. To solve this problem, a feature based modeller is developed in this study, which makes it possible to communicate between design and manufacturing through features. The modeller has feature, the concept of semi-bounded plane is introduced, and implemented as a B-rep sheet model using half-edge data structure. The features are then created on a part by local modification of the boundary on a part based on feature template information. This approach generalizes the modelling of features in a geometry model.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.10a
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• pp.304-310
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• 2001

Flow pulsation often causes vibration and noise in piping systems and therefore has been a troublesome concern for fluid system engineers. According to frequency increase in this paper under the influence wave form of velocity in springly flow and viscosity are drop coefficient of viscosity become increase so that impedance and resistance. The transient variations of flow rate are measured by a modified impedance tube method which is realized by virtue of the present analytical technique. At pipe line in order to eliminate vibration, confirm happened intermittently impedance characteristics. We make a test and frequency analysis and have to minimize obstructive component at hydraulic circuit.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.16 no.12 s.117
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• pp.1262-1271
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• 2006

Using the physics-based model for the vibration isolation system, the model uncertainties are described. With the model including parameter perturbations, the robust controller to meet the robust performance and stability is designed through $\mu$-synthesis by DK-iteration. The order of controller is reduced by virtue of Hankel norm approximation technique to allow the efficient implementation in the real-time experimental environment without any performance degradation. The performance of the reduced $\mu$-controller is accessed in comparison with the original one. The experiments validate the superiority of the proposed control scheme against the model uncertainties and its applicability with varying payload.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.3
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• pp.201-207
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• 2004

High speed rotating airflow inside a HDD chamber causes sub-micron scale disk vibration that could generate significant TMR problems in most of current HDD products. Many publications are presented for the reduction of airflow excitation. One of the most effective methods widely adopted in high-end HDD products is SqueezeAir Bearing Plate (SABP). However, because of its tight assembly clearance between the damper and disk, this method could not be easily implemented in volume production. This article presents a disk damper design that is modified to be feasible for volume production by virtue of a new airflow modeling method.

• Women's Health Nursing
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• v.14 no.2
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• pp.124-130
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• 2008

Purpose: The purpose was to identify marriage expectation and related factors among college students. Method: Data was collected by questionnaires from 329 college students in K university in Daegu. The data was analyzed using descriptive statistics, t-test, ANOVA, Pearson correlation coefficients, and stepwise multiple regression. Result: Marriage expectation among college students was significantly different according to gender, age and opportunities for employment. Marriage expectation among college students correlated with sex role attitudes. Significant predictors influencing marriage expectation were age, opportunities for employment, mother's job, and sex role attitudes, A combination of these predictors accounted for 10.3% of the variance in marriage expectation. Conclusion: These findings show that marriage expectation is influenced by age, opportunities for employment, mother's job, and sex role attitudes. Therefore when nursing interventions are developed to improve marriage expectation, these factors need to be considered.

• Journal of the Korean Mathematical Society
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• v.49 no.3
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• pp.515-536
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• 2012

This work focuses on the general decay stability of nonlinear stochastic differential equations with unbounded delay. A Razumikhin-type theorem is first established to obtain the moment stability but without almost sure stability. Then an improved edition is presented to derive not only the moment stability but also the almost sure stability, while existing Razumikhin-type theorems aim at only the moment stability. By virtue of the $M$-matrix techniques, we further develop the aforementioned Razumikhin-type theorems to be easily implementable. Two examples are given for illustration.

• Structural Engineering and Mechanics
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• v.26 no.4
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• pp.377-392
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• 2007

A discrete sliding mode control (SMC) method based on hybrid model of neural network and nominal model is proposed to reduce the vibration of flexible structures, which is a robust active controller developed by using a sliding manifold approach. Since the thick boundary layer will reduce the virtue of SMC, the multilayer feed-forward neural network is adopted to model the uncertainty part. The neural network is trained by Levenberg-Marquardt backpropagation. The design objective of the sliding mode surface is based on the quadratic optimal cost function. In course of running, the input signal of SMC come from the hybrid model of the nominal model and the neural network. The simulation shows that the proposed control scheme is very effective for large uncertainty systems.

• Architectural research
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• v.9 no.2
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• pp.19-25
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• 2007

The changes of prison facilities in the age of Enlightenment and Industrial Revolution, implies viewpoints architectural space as a representation of power. The aim of the study is to examine the structuralistic approach based on two authors of Michel Foucault and Robin Evans. Both texts are summarized and analyzed to make comparison. While Foucault concentrates upon the ideas relating to punishment which preceded and led to the prison being adopted, Evans regards the reality of punishment as it was executed in its architectural context. The study compares the fundamental difference between the two texts; the approach that each author takes with regard to the central issue of the history of penality. These two different interpretations dictate the framework of each discourse and has resulted a number of different notions of ideas. By comparing divergence and convergence of the texts, the study analyzes each author's methodology, theoretical position and notions of prison. Keywords are also extracted to articulate the study and each author's arguments as well.

• Journal of Korean Library and Information Science Society
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• v.35 no.2
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• pp.31-45
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• 2004

The purpose of this study is analyze physical and textual characteristics of the fold screen with Gosi(고시), tour ancient poems own by Beopjusa temple(법주사) in Mt. Sokrisan(속리산). The calligraphic specimen of this fold screen is written by King Seonjo(선조), and it seems to be made by between 1725 and 1758. On the view of physical point, the size of the fold screen is 190.0cm high, and 67.2cm wide each fold. And its format is made by 8 fold screen and its calligraphic style is a ‘cursive’ style. It was printed by wood block printing with chinese ink on the Geonji(견지). On the view of textual point, the fold screen of Gosi(고시) is consist of four ancient poems, and its content is describe to yearning for the appearance of the true gentleman possessed with high principles and virtue. And the four ancient poems is arranged by a well organized passage.