• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.733-736
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• 2003

This paper presents two systems of two-stage electrohydraulic servovalve with a nozzle-flapper pilot stage, which is controlled by stack-type piezoelectric elements. Two flapper moving mechanisms proposed in this research can compensate for the hysteresis problem and thermal expansion of the piezoelectric elements. The experimental results show that the first flapper moving mechanism has the frequency response of over 500 Hz and the second one has the response of over 600 Hz. And the first simplified servovalve system rising the first flapper moving mechanism has the frequency response of about 150 Hz, and the second system has the response of about 300 Hz at the supply pressure of 210 bar

• 한국정밀공학회지
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• 제20권6호
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• pp.71-80
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• 2003

This paper presents a two-stage electrohydraulic servovalve with a nozzle-flapper pilot stage, which is controlled by stack-type piezoelectric elements. The flapper moving mechanism developed in this research can compensate for the hysteresis problem and thermal expansion of the piezoelectric elements. The experimental result shows that this flapper moving mechanism has the frequency response of about 600 Hz. And a simplified servovalve system using this flapper moving mechanism has the frequency response of about 300 Hz at the supply pressure of 210 bar.

• 대한기계학회논문집A
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• 제25권2호
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• pp.206-213
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• 2001

The positioner is an essential component of the control valve which is used to control quantity of the liquid in the pipe of chemical plants. In this paper, the experimental methodology for current pneumatic positioner was developed for the investigation of the static and dynamic characteristics of the positioner. The methodology was applied to evaluate response characteristics of two different positioners, which are current model in market and newly designed model. The experimental results of these two models were compared and analyzed.

• 한국정밀공학회지
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• 제16권1호통권94호
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• pp.42-48
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• 1999

A control method for a robot hand grasping a object in a partially unknown environment will be proposed, where a proximate sensor detecting the distance between the fingertip and object was used. Particularly, the finger joints were driven servo-pneumatically in this study. Based on the proximate sensor signal the finger motion controller could plan the grasping process divided in three phases ; fast aproach, slow transitional contact and contact force control. That is, the fingertip approached to the object with full speed, until the output signal of the proximate sensor began to change. Within the perating range of the proximate sensor, the finger joint was moved by a state-variable feedback position controller in order to obtain a smooth contact with the object. The contact force of fingertip was then controlled using the blocked-line pressure sensitivity of the flow control servovalve for finger joint control. In this way, the grasping impact could be reduced without reducing the object approaching speed. The performance of the proposed grasping method was experimentally compared with that of a open loop-controlled one.

• 패션비즈니스
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• 제12권2호
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• pp.12-27
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• 2008

The purpose of this study is to study main characters' (Roxie Hart, Velma Kelly) costumes and color images in the movie "Chicago". First, regarding the costumes and color images in characters, Roxie's straight silhouette slip in skin tone reflected her frailty and monotonous routines in reality. On the other hand, a white beaded dress showed her fame-hungry and self-absorption in fantasy. Also, a low waistline blue dress and a see-through black dress with a white collar were to disguise her guilt and draw sympathy to win a suitcase. Black and contrasting colors of red and blue body-suit style dresses expressed Velma's sensual attraction, aggressiveness, and desperation. Second, these images were reinforced by color images in the backgrounds in the film. On the scene of Velma's 'cell block tango', black and red showed her strong character. Contrasting colors of the red and blue expressed Velma's desire and despair in her act of 'the desperation'. As for images of black color on Roxie's stages, they represented her self-absorption and frustration of failing to attract public attention. On the ending of duet performance of Roxie and Velma, the yellow of the background expressed success and joy in life.

• 패션비즈니스
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• 제2권3호
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• pp.55-72
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• 1998

The purpose of this study is for consideration of the flapper fashion (1924-1928) in Jazz Age (1919-1929) of America and the influences of it on modern fashion. This study is started from the latest fashion trend which is pursuing it's inspiration into the Jazz Age, the 20s. The etimology of 'flapper' was based on mines is 'flap' such as 'flutter of skirt hemline', 'hands', 'arms', 'wings' and a slang which was applied to young women from 1830. In 20th century it has meant not only new American women but also their fashion and attitude. The designs of flapper fashion were expressed by simplicity, functionality, nudity and rhythm. Simplicity was the best value of this time and the simple image was considered the smartest. Functionality was represented by straight boyish style and loose baggy silhouette that was related to free dome. Nudity was expressed by revealing of legs, arms, backs in shapes and see-through by materials. It was related to sexual attraction and point to youth. Rhythm of flapper fashion expressed optical effect of movement. Using of light material was deep related to freedom of flappers, speed, rhythmical Jazz and dancing. The influences of flapper fashion were giving an opportunity that changed fashion leader from high class to young popular group and simple design of flapper fashion effected to modernization and popularization of American apparel business. And it influenced American casual fashion which was known as brightness, youth and openhearted mood. So flapper fashion can be reganded as the starting point of the street fashion of the 20th century.

• 대한기계학회논문집
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• 제11권6호
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• pp.982-990
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• 1987

본 연구에서는 참고문헌(12)에서 배제된 머플러와 플래퍼밸브의 운동을 추가 시킴으로써 앞의 모델보다 실제장치에 근접시켜 보다 정확한 열적 및 동적거동을 예측 하고, 또한 컴퓨터 시뮬레이션의 수행시 계산시간을 줄여 정상운전상태의 결과를 얻고 자 한다.

• 한국가정과교육학회지
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• 제15권3호
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• pp.13-28
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• 2003

본 연구에서는 아동들이 자발적 독자적으로 학습할 수 있는 체계적인 인터넷 기반 아동소비자 교육프로그램을 개발하고, 소비자교육프로그램의 효과를 분석하고자 하였다. 효과 검증은 학업의 성취를 파악하기 위한 소비자지식, 소비자역할태도, 소비자기능의 변화와 인터넷기반 학습에 대한 아동들의 흥미도로 분석하고자 하였다. 인터넷 기반 아동소비자 교육프로그램을 개발하기 위한 연구방법은 하이퍼미디어 학습환경에서의 교육프로그램 개발 절차이고, 소비자교육프로그램 적용후 학습효과를 검증하기 위한 방법은 사전-사후 실험설계법이다. 개발한 소비자교육 프로그램은 6개 영역 즉 소비자의 개념. 욕구와 희소성, 광고, 구매시 주의점 소비자권리의 소개, 소비자문제와 해결로 구성하였으며 각 영역 내에서 필수적으로 다루어져야할 개념들을 구조화하여 총51개의 화면으로 완성하였다. 프로그램의 구현 저작도구는 매크로미디어 플래쉬5였다. 소비자교육프로그램의 효과 측정을 위해 K시의 A초등학교 40명을 대상으로 소비자교육을 실시하였고 사전-사후검사를 하였다. 아동소비자 교육프로그램으로 학습한 후의 효과를 학업성취와 학습흥미 측면에서 분석한 결과, 소비자지식수준이 유의미하게 향상되었고, 소비자역할 태도에서도 유의미하게 긍정적인 변화를 보였다. 또한 아동소비자들은 본 연구에서 개발한 프로그램으로 학습하는 것에 상당한 흥미를 보였는데 특히 직접 체험을 해보는 내용이나 화면설계가 역동적인 경우 더욱 흥미가 높았다. 현 교육과정에서 아동기부터 소비자교육이 활성화되기 위해서는 인터넷기반 소비자교육 프로그램을 다양하게 개발하는 것이 학습효과와 흥미 측면에서 유용하며 필수적이다.