• Title/Summary/Keyword: closed forms

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A Study on the Characteristics of Grotesque in Contemporary Fashion -Focused on since the 1990's- (현대패션의 그로테스크젝 특성에 관한 연구-1990년대 이후를 중심으로-)

  • Nam Mi-Hyun;Park Myung-Hee
    • Journal of the Korean Society of Costume
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    • v.54 no.8
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    • pp.147-162
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    • 2004
  • The purpose of this study is to investigate the characteristics of Grotesque in Contemporary Fashion. The study selected the 1990's or after fashion material by the material of both $pr{\hat{e}}t-{\grave{a}}-porter$ collection and haute couture collection based on Europe. These days, the characteristics of grotesque have been categorized into four groups based on the theory of representative scholars of the Post Modernism era. The results are as follows. ${\cdot}$ The devilism creates shocking and destructive cruelty and fear by using frightening object and mysterious and devilish motif which symbolize the death of fashion ${\cdot}$ Hatred produces physical destroy of human body, anatomical expression inside human body, cruelty by naked sex expression, pains, cruel treatment, disillusion and unpleasantness, which have been caused by the disturbance and ideological confrontation of the society, and is said to be a kind of self-confession against dislike and fear of the disclosure of human existence. ${\cdot}$ Playfulness distorts and exaggerates clothes and human body forms, and produces abnormality and mystery because of vague sex identity. The playfulness of fashion can open fixed and closed world and lead it flexibly. ${\cdot}$ Heterogeneity is divided into both primitiveness and virtuality The primitiveness distorts or transforms human body through the human body decoration of primitive race, and expresses a grotesque form combining human being and other animals. It gives a question to the existence of alienated and suppressed life through the world. in which everything is mixed and not separated. The virtuality introduces not only cyborg form combining human being and machines but also state of the art technology factors, so that it emphasizes non-mechanical and non-human grotesque images.

Effect of the Holding Temperature and Vacuum Pressure for the Open Cell Mg Alloy Foams

  • Yue, Xue-Zheng;Hur, Bo-Young
    • Korean Journal of Materials Research
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    • v.22 no.6
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    • pp.309-315
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    • 2012
  • Metal foam has many excellent properties, such as light weight, incombustibility, good thermal insulation, sound absorption, energy absorption, and environmental friendliness. It has two types of macrostructure, a closed-cell foam with sealed pores and an open-cell foam with open pores. The open-cell foam has a complex macrostructure consisting of an interconnected network. It can be exploited as a degradable biomaterial and a heat exchanger material. In this paper, open cell Mg alloy foams have been produced by infiltrating molten Mg alloy into porous pre-forms, where granules facilitate porous material. The granules have suitable strength and excellent thermal stability. They are also inexpensive and easily move out from open-cell foamed Mg-Al alloy materials. When the melt casting process used an inert gas, the molten magnesium igniting is resolved easily. The effects of the preheating temperature of the filler particle mould, negative pressure, and granule size on the fluidity of the open cell Mg alloy foam were investigated. With the increased infiltration pressure, preheat temperature and granule sizes during casting process, the molten AZ31 alloy was high fluidity. The optimum casting temperature, preheating temperature of the filler particle mould, and negative pressure were $750^{\circ}C$, $400-500^{\circ}C$, and 5000-6000 Pa, respectively, At these conditions the AZ31 alloy had good fluidity and castability with the longest infiltration length, fewer defects, and a uniform pore structure.

Nonlinear thermal buckling behavior of functionally graded plates using an efficient sinusoidal shear deformation theory

  • Bouiadjra, Rabbab Bachir;Bedia, E.A. Adda;Tounsi, Abdelouahed
    • Structural Engineering and Mechanics
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    • v.48 no.4
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    • pp.547-567
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    • 2013
  • Nonlinear behavior of functionally graded material (FGM) plates under thermal loads is investigated here using an efficient sinusoidal shear deformation theory. The displacement field is chosen based on assumptions that the in-plane and transverse displacements consist of bending and shear components, and the shear components of in-plane displacements give rise to the sinusoidal distribution of transverse shear stress through the thickness in such a way that shear stresses vanish on the plate surfaces. Therefore, there is no need to use shear correction factor. Unlike the conventional sinusoidal shear deformation theory, the proposed efficient sinusoidal shear deformation theory contains only four unknowns. The material is graded in the thickness direction and a simple power law based on the rule of mixture is used to estimate the effective material properties. The neutral surface position for such FGM plates is determined and the sinusoidal shear deformation theory based on exact neutral surface position is employed here. There is no stretching-bending coupling effect in the neutral surface-based formulation, and consequently, the governing equations and boundary conditions of functionally graded plates based on neutral surface have the simple forms as those of isotropic plates. The non-linear strain-displacement relations are also taken into consideration. The thermal loads are assumed as uniform, linear and non-linear temperature rises across the thickness direction. Closed-form solutions are presented to calculate the critical buckling temperature, which are useful for engineers in design. Numerical results are presented for the present efficient sinusoidal shear deformation theory, demonstrating its importance and accuracy in comparison to other theories.

The Effects of Augmented Somatosensory Feedback on Postural Sway and Muscle Co-contraction in Different Sensory Conditions

  • Kim, Seo-hyun;Lee, Kyung-eun;Lim, One-bin;Yi, Chung-hwi
    • Physical Therapy Korea
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    • v.27 no.2
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    • pp.126-132
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    • 2020
  • Background: Augmented somatosensory feedback stimulates the mechanoreceptor to deliver information on bodily position, improving the postural control. The various types of such feedback include ankle-foot orthoses (AFOs) and vibration. The optimal feedback to mitigate postural sway remains unclear, as does the effect of augmented somatosensory feedback on muscle co-contraction. Objects: We compared postural sway and ankle muscle co-contraction without feedback (control) and with either of two forms of somatosensory feedback (AFOs and vibration). Methods: We recruited 15 healthy subjects and tested them under three feedback conditions (control, AFOs, vibration) with two sensory conditions (eyes open, or eyes closed and the head tilted back), in random order. Postural sway was measured using a force platform; the mean sway area of the 95% confidence ellipse (AREA) and the mean velocity of the center-of-pressure displacement (VEL) were assessed. Co-contraction of the tibialis anterior and gastrocnemius muscles was measured using electromyography and converted into a co-contraction index (CI). Results: We found significant main effects of the three feedback states on postural sway (AREA, VEL) and the CI. The two sensory conditions exerted significant main effects on postural sway (AREA and VEL). AFOs reduced postural sway to a level significantly lower than that of the control (p = 0.014, p < 0.001) or that afforded by vibration (p = 0.024, p < 0.001). In terms of CI amelioration, the AFOs condition was significantly better than the control (p = 0.004). Vibration did not significantly improve either postural sway or the CI compared to the control condition. There was no significant interaction effect between the three feedback conditions and the two sensory conditions. Conclusion: Lower-extremity devices such as AFOs enhance somatosensory perception, improving postural control and decreasing the CI during static standing.

Ultimate Strength Analysis of Stiffened Plate with Minor Collision Damage (작은 충돌손상을 가진 보강판의 최종강도 해석)

  • Lee, Tak-Kee;Rim, Chae-Whan
    • Journal of Ocean Engineering and Technology
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    • v.21 no.4
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    • pp.34-37
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    • 2007
  • The safety of ships is one of the most important concerns in terms of the environment and human life. A ship in bad condition is likely to be subject to accidents, such as collision and grounding. When a ship has minor collision damages in the form of circle or ellipse, its ultimate strength will be reduced. It is important to evaluate the reduction ratio of a ship's ultimate strength that results from damages. The strength reduction of a plate with a cutout in the form of hole has been treated by many researchers. A closed-form formula for the reduction of ultimate strength of a plate, considering the effect of several forms of cutout, has been suggested. However, the structure of ships is composed of plates and stiffeners so-called stiffened plates and it is likely that plates and stiffeners will be damaged together in collisions. This paper investigates the effect of minor collision damages on the ultimate strength of a stiffened plate by using numerical analysis. For this study, the deformed shape of minor collision damages on a stiffened plate was made by using a contact algorithm and was used as the initial shape for ultimate stress analysis. Then, a series of nonlinear FE analyses was conducted to investigate the reduction effects on the ultimate strength of the stiffened plate. The boundary conditions were simply supported at all boundaries, and the tripping of stiffener was neglected. The results are presented in the form of reduction ratio between the ultimate strength of an original, intact stiffened plate and that of a damaged stiffened plate.

A New Approach to the Analysis of Continuous Beams (연속(連續)보의 해석(解析)에 관한 새로운 방법(方法)-모멘트 분배법(分配法)의 정식화(定式化))

  • Yang, Chang Hyun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.10 no.4
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    • pp.25-33
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    • 1990
  • The moment distribution method has been widely used for almost sixty years as an approximate method for the analysis of structural frames. The method is to calculate the end moments of structural members by iterative hand calculation. This study presents developements of closed form formulas which are derived basically from the moment distribution procedures. These formulas may provide simple forms and exact results which would overcome the disadvantages of the conventional moment distribution mothod, that is, approximation of the results and complexity of the procedures of the method. The proposed formulas may become one of the new procedures for analysis of statically indeterminate frames, and contribute specifically to the effective drawing of influence lines of continuous beams, which will provide a great deal of assistance in practical design of structures.

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An Adaptive Moving Average (A-MA) Control Chart with Variable Sampling Intervals (VSI) (가변 샘플링 간격(VSI)을 갖는 적응형 이동평균 (A-MA) 관리도)

  • Lim, Tae-Jin
    • Journal of Korean Institute of Industrial Engineers
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    • v.33 no.4
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    • pp.457-468
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    • 2007
  • This paper proposes an adaptive moving average (A-MA) control chart with variable sampling intervals (VSI) for detecting shifts in the process mean. The basic idea of the VSI A-MA chart is to adjust sampling intervals as well as to accumulate previous samples selectively in order to increase the sensitivity. The VSI A-MA chart employs a threshold limit to determine whether or not to increase sampling rate as well as to accumulate previous samples. If a standardized control statistic falls outside the threshold limit, the next sample is taken with higher sampling rate and is accumulated to calculate the next control statistic. If the control statistic falls within the threshold limit, the next sample is taken with lower sampling rate and only the sample is used to get the control statistic. The VSI A-MA chart produces an 'out-of-control' signal either when any control statistic falls outside the control limit or when L-consecutive control statistics fall outside the threshold limit. The control length L is introduced to prevent small mean shifts from being undetected for a long period. A Markov chain model is employed to investigate the VSI A-MA sampling process. Formulae related to the steady state average time-to signal (ATS) for an in-control state and out-of-control state are derived in closed forms. A statistical design procedure for the VSI A-MA chart is proposed. Comparative studies show that the proposed VSI A-MA chart is uniformly superior to the adaptive Cumulative sum (CUSUM) chart and to the Exponentially Weighted Moving Average (EWMA) chart, and is comparable to the variable sampling size (VSS) VSI EWMA chart with respect to the ATS performance.

A Selectively Cumulative Sum (S-CUSUM) Control Chart with Variable Sampling Intervals (VSI) (가변 샘플링 간격(VSI)을 갖는 선택적 누적합 (S-CUSUM) 관리도)

  • Im, Tae-Jin
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2006.11a
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    • pp.560-570
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    • 2006
  • This paper proposes a selectively cumulative sum (S-CUSUM) control chart with variable sampling intervals (VSI) for detecting shifts in the process mean. The basic idea of the VSI S-CUSUM chart is to adjust sampling intervals and to accumulate previous samples selectively in order to increase the sensitivity. The VSI S-CUSUM chart employs a threshold limit to determine whether to increase sampling rate as well as to accumulate previous samples or not. If a standardized control statistic falls outside the threshold limit, the next sample is taken with higher sampling rate and is accumulated to calculate the next control statistic. If the control statistic falls within the threshold limit, the next sample is taken with lower sampling rate and only the sample is used to get the control statistic. The VSI S-CUSUM chart produces an 'out-of-control' signal either when any control statistic falls outside the control limit or when L-consecutive control statistics fall outside the threshold limit. The number L is a decision variable and is called a 'control length'. A Markov chain model is employed to describe the VSI S-CUSUM sampling process. Some useful formulae related to the steady state average time-to signal (ATS) for an in-control state and out-of-control state are derived in closed forms. A statistical design procedure for the VSI S-CUSUM chart is proposed. Comparative studies show that the proposed VSI S-CUSUM chart is uniformly superior to the VSI CUSUM chart or to the Exponentially Weighted Moving Average (EWMA) chart with respect to the ATS performance.

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Analysis of Modified Digital Costas Loop Part I : Performance in the Absence of Noise (변형된 디지털 Costas Loop에 관한 연구 (I) 잡음이 없을 경우의 성능 해석)

  • 정해창;은종관
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.19 no.2
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    • pp.38-50
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    • 1982
  • A new type of digital phase-locked loop (DPLL) called the modified digital Costas loop is proposed and analyzed. The main feature of the proposed loop is that the phase error detector of the loop has linear characteristic. This results from the use of the tan-1 (.) function in the loop. Accordingly, the DPLL can be characterized by a modulo-2$\pi$ linear difference equation. This paper is diveide into two parts. In Part I we describe the proposed system, and analyze the performance of the first-and second-order loops in the absence of noise by the Phase Plane technique. The locking ranges for the DPLL's to achieve exact locking independently of initial conditions have been obtained in closed forms. Also, the false lock and oscillation phenomena occurring under some initial conditions have been considered. These results have been verified by computer simulation. In Part ll we analyze the proposed system in the presence of noise. The steady state probability density function, mean and variance of the phase error have been obtained by solving the Chapman-Kolmogorov equation. These results will be presented in Part ll.

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Humors in Female Costumes Depicted in Genre Paintings in the Late Joseon Dynasty (조선후기 풍속화에 표현된 여성복식의 해학미)

  • Kwon, Ha-Jin;Kim, Min-Ja
    • Journal of the Korean Society of Costume
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    • v.60 no.2
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    • pp.35-50
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    • 2010
  • In this dissertation, the analysis of the study of female customs from late Joseon Dynasty and their genre painting to research humors and its aesthetic senses in that certain era. The purpose of the genre paintings is to look at general populations in an objective point of view and endeavor better value of public life style to embody clear understandings of humanity. The artists such as Hong-Do Kim and Youn-Bok Shin expressed their arts based on reasonable reality with sarcastic but humorous and creative ways to criticize the society's problems with clear statements. Therefore, the formative characters are realism, exaggeration and coloring of the whole arts that represents as innovative and original genre of it's time. Hong-Do Kim and Youn-Bok Shin expressed the women in society as open minded with versatile and refined looks in their paintings as the reality was repressed and closed mind for women figures in late Joseon Dynasty. The female customs in the paintings has both suppression and expression in their dresses and exaggerated shapes of accessories and the use of color were also found. All of these elements has the aesthetic values of satirized eroticism, the hint of next evolution of the late Joseon Era under the conservative disposition of social characters and freedom of expression of playfulness. These elements were new developments and a step forward of female 'sex' and expression of satirized eroticism. The exaggerated and distorted forms and accessories demonstrates unbalanced and asymmetrical elements in humorous characters and they include spontaneity. Also, using the five traditional color schemes of Korean art displays humor in playfulness of an art with splendid and purity, duality of positiveness and artless, smart and elegance looks.