• Journal of Sensor Science and Technology
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• v.6 no.1
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• pp.72-80
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• 1997

One of the concerns in micro fluidic valve designs is that of reverse direction leakage. This paper designs and fabricates a new fluidic valve to achieve zero leakage. The design uses flapper and nozzle elements. In the forward direction the working fluid pushes the flapper upward to allow flow. In the reverse direction, the flapper pushes against the orifice seat, and thus, no flow can be generated, unless the flapper or nozzle element breaks. The nozzle element fabrication involves fabricating an orifice by wet etching of (100) wafer, The flapper element fabrication involves $20{\mu}m$ deep patterning of the negative image of the flapper, followed by wet etching from backside. Flow experiments were conducted with DI water as the working fluid, and the results are compared to analytical predictions. The results show that the developed flapper-nozzle valve achieves a true diodic flow characteristic.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.1
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• pp.49-56
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• 2016

Flapper Valve of Korean Utility Helicopter(KUH-1) is an essential equipment in Environmental Control System(ECS) for pilot to perform flight mission. It provides pilots and crews with heating, ventilating and air conditioning. It has function of maintaining room temperature to sustain operational capability for pilot and crew. This paper summarizes pilot comments in flight test which are classified by cause of occurrence and the troubleshooting process about each comment. It also describes design improvements which was derived from troubleshooting and suggests verification results of flight test at low temperature.

• The Research Journal of the Costume Culture
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• v.26 no.1
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• pp.19-29
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• 2018

The purpose of this study is to examine the sociocultural meanings of flapper look in American society during the 1920s. Using the ProQuest database, I searched articles from The New York Times published between 1920 and 1929 for opinions and discussions on the flapper look. Keywords included "clothing," "dress," "fashion," and "flapper," and advertisements and articles on menswear, leisurewear, and bathing suits were excluded. In the resulting articles, I extracted the following sociocultural meanings: autonomy, activeness, practicality, attractiveness, and extravagance. Meanings were analyzed from the opinions and discussions focusing on skirt length, dresses that directly and indirectly exposed the body, heavy make-up, non-constricting underwear, the H-line dress, bobbed hair, hygiene, comfort, and consumption. In sum, the 1920s flapper look represented progressive characteristics such as autonomous and active womanhood and practicality, which matched the technological development of the time. However, the flapper look was commercialized and exploited to make women look attractive and extravagant. Even though American women had access to higher education, more economic power, and suffrage in the 1920s, they were limited in their ability to overcome social conventions and the power of consumerism. Understanding the double-sidedness of flapper look within the social context of the time would enhance the comprehension of the relationship between women's lifestyles and changing fashion.

• Journal of the Korean Society of Clothing and Textiles
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• v.24 no.2
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• pp.173-184
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• 2000

The purposes of this study is for consideration of the flapper image through the culture and novels in Jazz Age(1919∼1929) of America. The back ground of flapper fashion was Jazz. Jazz was one of the cultural languages which expressed liveness, noise, salacity, harmony of primitivity, modernity, innocence and freedom. In processing American had gotten economic power, the Jazz Age had new mood which was combined materialism and realitism. Environmental changes of life styles and development of mass culture of modern big cities could aid the birth of modern girls, flappers. They became the main group of new consumer and mass culture in new consciousness and freedom with independence. Their characteristics are confirmed from Fitzgerald's novels, This Side of Paradise and The Great Gatsby. As the results of above, the consciousness of flapper were rebellious attitude, liberalism and actualism. The designs of flapper fashion were expressed by simplicity, functionality, nudity and rhythm. The flapper images are as follows: First, they expressed modern image as a rebellious attitude. Second, flapper had a sensual image of freedom through rhythmical and speedy expression. Third, premature image for pursuing youth could be found. Therefore the changes of culture and women's life styles are very important points for fashion studies and the connecting fashion and other fields like novels is needed also for it.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.20 no.10
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• pp.976-982
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• 2010

This paper proposes a novel type of pressure control mechanism which can apply to vehicle ABS (anti-lock braking system) utilizing the piezoactuator based valve system associated with the pressure modulator. As a first step, a flapper-nozzle of a pneumatic valve system is devised by integrating the piezoacuator to the flexible beam structure. The dynamic modeling of the valve system is then undertaken and subsequently the governing equation of pressure control is derived considering the pressure modulator. A sliding mode controller is designed in order to achieve accurate pressure tracking control in the presence of actuator uncertainty as well as input pressure variation. It is shown through computer simulation that an accurate pressure tracking for sinusoidal motion whose magnitude is 40 bar is achieved by utilizing the proposed pressure control mechanism.

• Journal of the Korean Society of Costume
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• v.61 no.2
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• pp.1-19
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• 2011

As modern society advances, women's self-consciousness and attitudes toward beautiful appearances have changed. Amid this trend, the young and slim body of adolescent girls expressed in contemporary fashion incites fantasy on continuing youth among women. In modern society, women's youth is frequently regarded as a subject of consumption and a sex product in the mass media. In this regard, the study is focused on examining desire and psychology of worshipping women's youth and beauty in connection with flapper fashion in the 1920s. In the process, the study took a look at the social and cultural background of flapper fashion and conducted an analysis on formative characteristics and aesthetic sense of flapper fashion as follows: First, the formative characteristics include a short skirt that expresses straight lined shape and the beauty of exposure, lighter clothing, thick make-up, short hair style and black or vivid colors, and they lead to exceptional and innovative aesthetic sense in flapper fashion. Flapper fashion style is focused on completely denying outdated fashion worn by women in the age right before. Second, pursuit of mature, graceful and classical beauty that had continued in previous ages has gone through complete changes in the flapper era in the name of pursuit of youth, and the flapper fashion expresses sensual image through the exposure of slim arms and legs of a young girl. In the formative characteristics, aesthetic sense of youth and sensuality inherent in the flapper fashion was generated. Third, women's free-spirited lifestyle at that time and 'aesthetic sense of freedom and amusement that reflected the speed of machine civilization could be found in the flapper fashion. Material and decoration of the flapper fashion pertained to clothing that enabled a free expression through rapid movements. Aesthetic sense of the flapper fashion generated in the process could be defined as women's internal determination to express individual and free-spirited ideas through the use of fashion when tradition and order of the old age were torn down. And this aesthetic sense is continuously affecting modern fashion design.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.1
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• pp.54-62
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• 2000

The purpose of this study is to bring out the optimal design factors which effect on dynamic characteristics in the design of flow control servo valve with high response characteristics, and to verify the validity of the design factors. In this study, force feedback type flow control valve with nozzle/flapper and with no drain is studied. And, the effect of the parameters, such as fixed orifice, nozzle diameter, and maximum displacement between nozzle and flapper are analyzed. We have done simulations using the optimal design factors and simulink(Matlab) as a simulation tool, and verified the validity of our simulations by means of comparison our simulation results with an experimental results of another similar valve.

• The Research Journal of the Costume Culture
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• v.3 no.2
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• pp.261-275
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• 1995

This paper analyzes the parallelism between the art trend and the fashion. As a representative case, we consider the Modernism and the Flapper look. The Modernism rejected the tradition of the past and pursued something new. This trend was in parallel with the fashion called flapper look which was against the tradition and made drastic change. The factors which represent the spirit of the age the Modernism are the simplicity, the rejection of the tradition, the individualism and the subjectivity, the functionalism, the fragmentation of the self, and the straight line. We discuss the fashion style of the flapper look in terms of these factors.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.2
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• pp.151-160
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• 2000

An experimental and theoretical analysis for the improvement of dynamic characteristics and design of electro-hydraulic flow control servo valve are performed. The theoretical results are compared with the experimental step responses, and the important design parameters of an electro-hydraulic flow control servo valve are derived by using the simulation program. Simulation parameters of nozzle jet coefficient and orifice and spool valve discharge coefficient are given through experiment. The theoretical and experimental step response curves show that the valve gain depends on the fixed orifice and nozzle $ratio(R_on)$ and is maximum at $R_on=1.$ And drain orifice in the flapper - nozzle return line creates a small back pressure, which improves the performance fur the valve.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.331-336
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• 1995

In this past decade, industrial robot have substituted human workers successfully in certain areas, however, the applications are limited due to the shortcoming in their mechanism and control strategies. Many researchers, therefore, have focused on improving the mechanical and sensory capabilities. Developing mult-degree-of-freedom end effectors, in other words robot hands, is one of the topics that researchers have begun to improve the limitation. A set of direct drive type servo-pneumatic finger joint has been developed for a dexterous robot hand. To control the pneumatic finger joints, a prototype 4/3-way proportional control valve has been designed and tested as a preliminary, research for the control of the pneumatic finger joints. A series of experiments have been conducted to verify the performance characteristics of the valve and the conventional proportional error contral with minor-loop compensation has been used to control the anguar position of the finger joints.