• 한국의류학회지
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• 제33권10호
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• pp.1644-1654
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• 2009

The concentration of dye uptake and the fastness improved when cotton and silk fabrics were treated with chitosan, a natural polymer. In this study, the effect of chitosan treatment was reviewed after the printing of cotton and silk fabrics padded with chitosan. When the change of physical and mechanical properties of printed fabrics was reviewed (as the concentration of chitosan increased) the thickness and weight increased a little, and the air permeability increased significantly than those untreated with chitosan. The dye uptake increased, accompanying a darker color shade, and the wash fastness increased 1/2-1 grade. The analysis results of enlarged images of printed patterns indicated that the width and area deformations were minimal as the concentration of chitosan increased when compared to untreated fabrics. Therefore, the dyeability and pattern quality were excellent after printing the chitosan-treated cotton and silk fabrics with cochineal dyestuff.

• International Journal of Ocean System Engineering
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• 제2권3호
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• pp.139-150
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• 2012

This paper presents an improved guidance algorithm for autonomous underwater vehicles (AUV) in 3D space for generating smoother vehicle turn during the course change at the way-points. The way-point guidance by the line-of-sight (LOS) method has been modified for correcting the reference angles to achieve minimal calculation and smoother transition at the way-points. The algorithm has two phases in which the first phase brings the vehicle to converge to a distance threshold point on the line segment connecting the first two way-points and the next phase generates an angular path with smoother transition at the way-points. Then the desired angles are calculated from the reference and correction angles. The path points are regularly parameterized in the spherical coordinates and mapped to the Cartesian coordinates. The proposed algorithm is found to be simple and can be used for real time implementation. The details of the algorithm and simulation results are presented.

• 전기학회논문지
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• 제58권7호
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• pp.1281-1286
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• 2009

As a general radial configuration of power distribution system, the various researches have being studied to change a radial configuration to network one such as smart, intelligent and micro grid for loop operation. If a radial configuration changes to network, protective coordination comes to the biggest problem. When a typical protective algorithm is applied to loop distribution system protection, the interrupted section is expanded, therefore, reliability grows worse. This paper presents the new protective method being able to apply to loop distribution system with Distribution Automation System (DAS) which separate the minimal faulted section. Through contingency analysis of the sustained and momentary fault, we analyzed the influence for radial configuration and loop configuration using interrupted area and proved the effectiveness of proposed method.

• 한국실내디자인학회:학술대회논문집
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• 한국실내디자인학회 2003년도 춘계학술발표대회 논문집
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• pp.187-191
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• 2003

Modern interior design is expanding diversely, with the rapid development of technology and change of era. The basic of interior space that is rapidly changing consists of floor, wall and ceiling, and these are formed by materials, materials for structure or finishing materials. In the modern interior space, materials are utilized to present an atmosphere that meets the trend of the dissolution of post-modernism and the trend of minimalism. Accordingly, in this study, designers who take serious view on the relation of space and material, and the relation focusing on completed works, in modern interior design were investigated. The interrelation of the representation of each material, organic space, minimal space, and the space of Oriental fusion style were investigated through the works of modern interior designers, such as Karim Rashid and Ettore Sottsass.

• 기술사
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• 제33권4호
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• pp.68-71
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• 2000

Tideland reclamation in Korea has significant meanings both in securing the staple food supply and in enlarging the limited land resources. Environmentally, that significantly contributes in protecting the sea and the tidelands connected to a reclaimed area from the direct exposure to the environmental destruction by filtering the large volume of contaminant discharged from the inland. Furthermore, within few years after closing a sea dike. formulation of new tideland begins in wide area in front. Therefore, tideland reclamation should not be the one that must be unconditionally objected. Instead, the methodology should be wisely redirected to minimize the environmental disorder. It will be one viable alternative to proceed the tideland reclamation at medium- to small-scales environment-friendly bringing minimal environmental change in the sea.

• Journal of Korean Neurosurgical Society
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• 제41권5호
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• pp.323-326
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• 2007

Direct carotid-cavernous fistula [CCF] is a common post-traumatic disease. However, pseudoaneurysm formation after balloon occlusion is a rare complication. The author present such a case with review of the literature. A 26-year-old man involved in a motor vehicle accident as a driver. Only mild conjunctival injection and minimal exophthalmos on the right eye were noted after trauma. However, angiography revealed a direct CCF and dissection of the proximal intracranial internal carotid artery [ICA]. After first balloon occlusion of the CCF, the patient redeveloped fistula due to early deflation of the balloon. After the second balloon occlusion, pseudoaneurysm and diplopia were developed with the change of balloon position and shape. However, visual symptom spontaneously resolved and pseudoaneurysm was also decreased within 6 months after balloon occlusion.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2004년도 전력전자학술대회 논문집(1)
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• pp.312-315
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• 2004

This paper presents a tuning-free conditional integration anti-windup strategy for induction machine with Proportional-Integral (PI) type speed controller. The on/off condition of integral action is determined by the frequency domain analysis of machine torque command without a prior knowledge of set-point changes. There are no tuning parameters to be selected by users for anti-windup scheme. In addition, the dynamic performance of the proposed scheme assures a desired tracking response curve with minimal oscillation and settling time even in the change of operating conditions. This algorithm is useful in many high performance induction machine applications not to allow the oscillation and overshoot of speed/torque responses. The main idea can be extended to general applications such as chemical processes and industrial robots.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제52권12호
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• pp.616-623
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• 2003

Conventional P/PI speed controller of today's servo drives should be manually tuned the controller switching set-point by trial-and-errors, which may translate the drive system down-time and loss of productivity. The adjustable drive performance is heavily dependent on the quality of the expert knowledge and becomes inadequate in applications where the operating conditions change in a wide range, i.e., tracking command, acceleration/deceleration time, and load disturbances. In this paper, the demands on simple controls/setup are discussed for industry servo drives. Analyzing the frequency content of motor torque command, P/PI control mode switching is automatically performed with some prior knowledge of the mechanical dynamics. The dynamic performance of the proposed scheme assures a desired tracking response curve with minimal oscillation and settling time over the whole operating conditions. For comprehensive comparison of traditional P/PI control scheme, extensive test is carried out on actual servo system.

• Journal of the Korean Data and Information Science Society
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• 제14권4호
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• pp.997-1005
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• 2003

In this paper, the problem of determining optimal burn-in time is considered under a general failure model. There are two types of failure in the general failure model. One is Type I failure (minor failure) which can be removed by a minimal repair and the other is Type II failure (catastrophic failure) which can be removed only by a complete repair. In this model, when the unit fails at its age t, Type I failure occurs with probability 1 - p(t) and Type II failure occurs with probability p(t), $0{\leq}p(t)\leq1$. Under the model, the properties of optimal burn-in time maximizing mean time to the catastrophic failure during field operation are obtained. The obtained results are also applied to some illustrative examples.

• 음성과학
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• 제7권1호
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• pp.39-52
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• 2000

The present study investigates the clinical applicability of a new device which objectively measures nasal resonating vibration via piezoelectric vibratory sensor from 10 normal volunteers, 10 patients with definite hypernasality and 10 nasal polyposis patients. For the assessment of the hypernasality, the ratio of 'ng' to 'a' as well as that of 'mama' to 'papa' passages were used. For the evaluation of hyponasality, the ratio of nasal vibration post- to pre-induced cul-de-sac resonation was calculated. In the control group, the ratio of ng/a and mama/papa passages was larger than 8, while in the hypernasality group, the ratio was markedly lower. The vibratory signals of 'a' and 'ng' increased markedly in the control group and the hypernasality group after inducing cul-de-sac resonation, while in the hyponasality group, the change was minimal.