• Title/Summary/Keyword: self-stability

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Experimental Study on Comparison of Buoyancy Driven and Lewis Number Induced Self-excitations in Laminar Lifted Coflow-jet Flames. (층류 동축류 제트 부상화염에서 부력에 의한 자기진동과 루이스 수에 의한 자기진동 비교에 관한 실험적 연구)

  • Ban, Gyu Ho;Lee, Won June;Park, Jeong;Keel, Sang-In;Yun, Jin-Han;Lim, In Gwon
    • 한국연소학회:학술대회논문집
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    • 2014.11a
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    • pp.367-369
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    • 2014
  • A study on laminar coflow jet flames diluted with helium and nitrogen has been conducted to investigate self-excitations. The stability map was provided with a function of nozzle exit velocity and fuel mole fractions of propane or methane. The results show that there exist three types of self-excitations; (1) buoyancy-driven self-excitation (BDSE), (2) Lewis number induced self-excitation coupled with buoyancy (LCB) and (3) Lewis number induced self-excitation (LISE).

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A Study on Self-differentiation, Marital Conflict and Marital Satisfaction among Couples' (부부의 자아분화 수준에 따른 부부갈등과 결혼만족도에 관한 연구)

  • Han, Young-Suk
    • Korean Journal of Human Ecology
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    • v.16 no.2
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    • pp.259-272
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    • 2007
  • The purpose of this study was to investigate the effect of couples' self-differentiation by marital satisfaction according to couple's gender. The participants of the present study were 728 couples who lived in Chonbuk province. The data were collected by self-administered questionnaire method. Self-differentiation scale was consisted of such factors as emotional reactivity, I-position, emotional cut-off and fusion with others. The results of this research were as follows: First, there was significant difference in the level of total self-differentiation between husbands and wives. Second, there was significant difference in the levels of marital conflict and of marital satisfaction to levels of self differentiation. Third, self differentiation in both husbands and wives had an direct effect on marital satisfaction and stability through marital conflict. Fourth, marital conflict in both husbands and wives had a direct effect on marital satisfaction.

Self-Recurrent Wavelet Neural Network Based Direct Adaptive Control for Stable Path Tracking of Mobile Robots

  • You, Sung-Jin;Oh, Joon-Seop;Park, Jin-Bae;Choi, Yoon-Ho
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.640-645
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    • 2004
  • This paper proposes a direct adaptive control method using self-recurrent wavelet neural network (SRWNN) for stable path tracking of mobile robots. The architecture of the SRWNN is a modified model of the wavelet neural network (WNN). Unlike the WNN, since a mother wavelet layer of the SRWNN is composed of self-feedback neurons, the SRWNN has the ability to store the past information of the wavelet. For this ability of the SRWNN, the SRWNN is used as a controller with simpler structure than the WNN in our on-line control process. The gradient-descent method with adaptive learning rates (ALR) is applied to train the parameters of the SRWNN. The ALR are derived from discrete Lyapunov stability theorem, which are used to guarantee the stable path tracking of mobile robots. Finally, through computer simulations, we demonstrate the effectiveness and stability of the proposed controller.

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A Study on the Effects of Mobile Communicational Devices on the Emotional Stability of the Elder Person (모바일 통신기기 사용이 노인의 심리적 안정감에 미치는 영향에 관한 연구)

  • Kim, Soo-Yeoun;Choi, Myung-Sin;Chung, Chang-Duk;Hong, You-Sik
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.9 no.6
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    • pp.219-226
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    • 2009
  • This study is focused on examining the use of information and communication technology among the factors that contribute to the psychological stability of the aged. To identify the appreciation and experience of information and communication technology, we have itemized mobile technology and internet technology which are the most broadly utilized technologies by the elderly, and suggested a methodology to measure the effects that information and communication technology have on their psychological stability. We surveyed more than 100 people over 55 year old in Seoul. The findings of the study showed that the group of users who use wired internet and mobile technology are less depressed and have more self-esteem than the group of non-users. It was also shown that the more skilled they are at utilizing the technology, the less feelings of depression and loneliness, and the more self-esteem they have.

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Fashion Trend Preferences According to Clothing Consumption Values - Focusing on Career Women - (직장여성의 의복소비가치에 따른 패션트렌드선호경향)

  • Rha Soo-Im
    • Journal of the Korea Fashion and Costume Design Association
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    • v.6 no.3
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    • pp.67-81
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    • 2004
  • This research demonstrates clothing consumption values, fashion preferences of career women from the early 1920s to late 1930s. And having thorough understanding of values and preferences, allows us to establish marketing strategies for clothing companies. The main purpose of this study is (1) to formalize consumer group based upon the clothing consumption values, (2) to find for characteristics of consumer depending on classification of consumption value in clothing, (3) to understand the preferences of career women about fashion trends. Analyzing data was performed 292 copies, resulting factor analysis, Cluster analysis, X-test, Anova, Tukey test, t-test, frequency analysis, and reliability analysis. This paper showed 7 distinctive characteristics of career women about clothing consumption value. These characteristics can be listed as 1) value of brand image, 2) value of self-expression, 3) functional values, 4) epistemic values, 5) coordination values, 6) social values 7) psychological values. Importantly, brand image value became most significant aspects among 7 factors. Analyzing consumers based upon stated 7 factors, it was found that they are segregated into 4 groups; Self-expressive Group, Psychological Stability Group, Functional Group, Social Group. Secondly, for fashion trend preferences, self-expressive group, psychological stability group, and functional group favored Romantic Feminine Style respectively. Social Group showed preference in Nu-Basic'. The reason for such trend dealt with fabric materials and colors. Finally examining population statistics, younger generations showed more preferences in Nu-Basic', and consumers from ages of 26 to 28, 32 to 34 showed preferences in Romantic Feminine' regardless of their household income, clothing related expenditures, jobs, and education level. On the other hand, 'Modem Classic' was popular among college graduates and 'Paradise' was somewhat less popular among all ages except from ages of 32 to 34, consumers consumption 300,000Won to 400,000Won on clothing related expenditures. And 'Energy' seemed to attract more highly educated females, who had more than masters in degrees with over 300,000 to 400,000Won for clothing related expenditures.

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Large deflection behavior and stability of slender bars under self weight

  • Goncalves, Paulo B.;Jurjo, Daniel Leonardo B.R.;Magluta, Carlos;Roitman, Ney;Pamplona, Djenane
    • Structural Engineering and Mechanics
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    • v.24 no.6
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    • pp.709-725
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    • 2006
  • In this paper the buckling and post-buckling behavior of slender bars under self-weight are studied. In order to study the post-buckling behavior of the bar, a geometrically exact formulation for the non-linear analysis of uni-directional structural elements is presented, considering arbitrary load distribution and boundary conditions. From this formulation one obtains a set of first-order coupled nonlinear equations which, together with the boundary conditions at the bar ends, form a two-point boundary value problem. This problem is solved by the simultaneous use of the Runge-Kutta integration scheme and the Newton-Raphson method. By virtue of a continuation algorithm, accurate solutions can be obtained for a variety of stability problems exhibiting either limit point or bifurcational-type buckling. Using this formulation, a detailed parametric analysis is conducted in order to study the buckling and post-buckling behavior of slender bars under self-weight, including the influence of boundary conditions on the stability and large deflection behavior of the bar. In order to evaluate the quality and accuracy of the results, an experimental analysis was conducted considering a clamped-free thin-walled metal bar. As this kind of structure presents a high index of slenderness, its answers could be affected by the introduction of conventional sensors. In this paper, an experimental methodology was developed, allowing the measurement of static or dynamic displacements without making contact with the structure, using digital image processing techniques. The proposed experimental procedure can be used to a wide class of problems involving large deflections and deformations. The experimental buckling and post-buckling behavior compared favorably with the theoretical and numerical results.

Analysis of Taste of Middle-aged Korean Men Based on Self-image and Fashion style (한국 중년 남성의 자기이미지와 패션스타일 유형에 따른 취향 분석)

  • Kim, Hee-Yeon;Kim, Young-In
    • Journal of the Korean Society of Costume
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    • v.64 no.8
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    • pp.37-54
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    • 2014
  • The purpose of this study is to define the tastes of middle-aged Korean men by analyzing their characteristics, such as self-image, and fashion style. This study was carried out by using the Q methodology for survey research. The results of this study are as follows; First, the self-images of middle-aged men were classified into 'comfortable, calm, neat, and gentle,' 'realistic, active, sociable, and familiar,' 'sensible, emotional, romantic, and rational,' 'refined, emotional, luxurious, and sophisticated,' and 'aggressive, sensible, realistic, and rational.' Second, by analyzing the congruity of clothing form, fashion accessory, and fashion color types, this study was classified into the following 10 fashion styles: 'modern classic,' 'sophisticated,' 'town casual,' 'traditional casual,' 'comfortable,' 'chic casual,' 'contemporary,' 'gentle classic,' 'classic sporty,' and 'soft classic.' Third, this study analyzed the self-images and fashion styles of the men, and produced the following personal tastes of middle-aged men: 'success-oriented,' 'ability possession,' 'internal stability-oriented,' 'freedom-oriented,' 'self-satisfaction,' 'individuality compromise,' 'emotional release,' 'stability-oriented,' 'practicability-oriented,' and 'youth effort' types. By combining those types with social dimensions, this study produced the following tastes of middle-aged men: 'stabilized traditions,' 'achievements with high sociality,' 'youthful individuality,' 'active self-realization,' and 'realistic, logical pursuit.' The results of this study can be used as a meaningful data for developing the marketing strategy, which reflects the middle-aged men's changed tastes.

Indirect self-tuning regulator with loopshaping

  • Han, Seong-Ho;Yoshihiro, Takita
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.47.6-47
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    • 2001
  • In this paper a new indirect robust self-tuning regulator is proposed including an inverse system of a plant and a robust compensator such that it achieves the desired frequency shape specified by solving the mixed H$\infty$ sensitivity problem within a prescribed tolerance in the H$\infty$ norm. Consequently, in the proposed self-tuning regulator, robust stability is guaranteed in spite of the identification error.

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Self-similarity in the equation of motion of a ship

  • Lee, Gyeong Joong
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.6 no.2
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    • pp.333-346
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    • 2014
  • If we want to analyze the motion of a body in fluid, we should use rigid-body dynamics and fluid dynamics together. Even if the rigid-body and fluid dynamics are each self-consistent, there arises the problem of self-similar structure in the equation of motion when the two dynamics are coupled with each other. When the added mass is greater than the mass of a body, the calculated motion is divergent because of its self-similar structure. This study showed that the above problem is an inherent problem. This problem of self-similar structure may arise in the equation of motion in which the fluid dynamic forces are treated as external forces on the right hand side of the equation. A reconfiguration technique for the equation of motion using pseudo-added-mass was proposed to resolve the self-similar structure problem; specifically for the case when the fluid force is expressed by integration of the fluid pressure.