• Title/Summary/Keyword: opening phenomenon

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Study of Shock Tube for Wave Phenomenon in High Speed Railway Tunnel(1) - On the characteristics of Compression Wave - (고속철도 터널에서 발생하는 파동현상에 관한 충격파관의 연구(1) - 압축파의 특성에 대하여 -)

  • ;松尾一泰
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.18 no.10
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    • pp.2686-2697
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    • 1994
  • When a railway train enters a tunnel at high speed, a compression wave is formed in front of the train and propagates along the tunnel. The compression wave subsequently emerges from the exit of the tunnel, which causes an impulsive noise. In order to estimate the magnitudes of the noises and to effectively minimize them, the characteristics of the compression wave propagating in a tunnel must be understood. In the present paper, the experimental and analytical investigations on the attenuation and distortion of the propagating compression waves were carried out using a model tunnel. This facility is a kind of open-ended shock tube with a fast-opening gate valve instead of a general diaphragm. One-dimensional flow model employed in the present study could appropriately predict the strength of the compression wave, Mach number and flow velocity induced by the compression wave. The experimental results show that the strength of a compression wave decreases with the distance from the tunnel entrance. The decreasing rate of the wave strength and pressure gradient in the wave is strongly dependent on the strength of the initial compression wave at the tunnel entrance.

Moreton Wave and EUV Wave Associated with the 2010 February 7 and 2010 August 18 Flares

  • Asai, Ayumi;Isobe, Hiroaki;Takasao, Shinsuke;Shibata, Kazunari
    • The Bulletin of The Korean Astronomical Society
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    • v.36 no.2
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    • pp.83.1-83.1
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    • 2011
  • Solar flares are very spectacular, and are associated with various phenomena. Coronal shocks or disturbances are one of such flare-related phenomena. Although Moreton waves and X-ray waves are well explained with MHD first mode shocks propagating in the corona, there still remains a big problem on the nature of the waves, since they are very rare phenomena. On the other hand, EIT waves (or EUV waves) have been paid attention to as another phenomenon of coronal disturbances. However, the physical features (velocity, opening angle, and so on) are much different from those for Moreton waves and X-ray waves. We report detailed features of the coronal disturbances associated with the 2010 February 7 and the 2010 August 18 flares. For the former flare we analyzed the H-alpha images obtained by SMART at Hida Observatory, Kyoto University, Japan and by a flare telescope at National Astronomical Observatory of Japan, the X-rays images taken by Hinode/XRT, and the EUV images obtained by the both satellites of STEREO, and found the Moreton wave, X-ray wave, and EIT wave, simultaneously. In the latter flare, on the other hand, we observed a very fast EUV wave in EUV images taken by SDO/AIA. The propagating speed is comparable to the MHD first mode wave, while there is no obvious evidence of shocks for this flare. From these results, we discuss the nature of coronal disturbances.

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Life Estimation of Organic Light Emission Diode by Accelerated Test (유기발광 다이오드의 가속 수명 시험에 관한 연구)

  • Choi, Young-Tea;Cho, Jai-Rip
    • Journal of the Korea Safety Management & Science
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    • v.12 no.4
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    • pp.61-66
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    • 2010
  • Organic light emitting diode(OLED) has been developed fast from 1963 when electric light emitting phenomenon was discovered. PMOLED(passive matrix OLED) is producted earlier than AMOLED(active matrix OLED). PMOLED is mainly mounted at sub display, but AMOLED is mounted at main display. Nowadays AMOLED is expanded to PMP(portable multimedia players), navigation and TV market. Even thought OLED's market is opening to many applications, OLED's life is worried until now. If we know about OLED's real life, we need time to test so much time over 20,000hrs. Realistically, there is difficult to test such as long time with products from the information-technology sector having a short life cycle. In this paper, we study about OLED's accelerated test to reduce life test by current. We can design OLED's accelerated life model by the result of test. The model consists of design variables like ratio of light emitting, organic material structure, condition of aging, etc. In conclusion, this model can be applied to study about organic material, machine and manufacturing process etc, and also it's possible to develop a method of manufacturing process & materials, so we need to study on the subject of this paper continuously.

As Rumi Travels along the Silk Road in Feminist Costume: Shafak's The Forty Rules of Love

  • GHANDEHARION, AZRA;KHAJAVIAN, FATEMEH
    • Acta Via Serica
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    • v.4 no.1
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    • pp.71-86
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    • 2019
  • Transnational exchange has been an inseparable part of both the ancient and modern Silk Road. This paper shows how Rumi (1207-1273), a famous Persian Sufi poet, travels along the Silk Road in the $21^{st}$ century. With the birth of a Rumi phenomenon in the West, Silk Road artists have rediscovered and adapted him for different purposes. Elif Shafak, the Turkish-British novelist and women's rights activist, espouses feminist beliefs in her bestseller, The Forty Rules of Love (2010). Benefiting from the views of feminist theorists like Woolf, de Beauvoir and Friedan, this paper reveals how Shafak appropriates Rumi for her feminist purposes. Forty Rules of Love's protagonist, Ella Rubinstein is analyzed, compared and contrasted with her former literary counterparts Pinhan and Zeliha, heroines of Shafak's previous novels. By adapting Rumi's definition of equality, Shafak shows how egalitarianism must pervade the relationship between women and men. The adaptation of Rumi's ideas regarding the equality of sexes finds a different dimension when Shafak reveals that all humanity possesses femininity and masculinity at the same time. By means of ideas prevalent in the ancient Silk Road, the five classical elements theory, and the yin and yang principle, Shafak portrays unity within contradictions. It is concluded that although individuals might belong to different typologies of the five symbolic elements of nature, they can at the same time complement one another's inharmonious personalities peacefully. The process of integration of female and male sexes can be expedited by opening up one's heart to a universal love.

The Effect of Deceptive Brand Image on Consumer Purchase Intention: Empirical Evidence from Iraqi Market

  • ALQAYSI, Sahar Jalal;ZAHARI, Abdul Rahman
    • The Journal of Asian Finance, Economics and Business
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    • v.9 no.6
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    • pp.207-217
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    • 2022
  • In recent years, the Iraqi market witnessed a large opening that resulted from the entry of many different products with an absence of government regulations. As a result, marketing deception practices have emerged as a new phenomenon. This study examines the effect of deceptive brand image on consumer purchase intention, with consumer attitude as a mediator. A quantitative method was applied in the form of a questionnaire distributed to shoppers at Carrefour Supermarket in Erbil, Kurdistan Region of Iraq. A random sampling technique was conducted. Subsequently, 200 questionnaires were distributed, and 175 valid questionnaires were analyzed, indicating an 87% response rate. Partial least squares structural equation modelling (PLS-SEM) has been utilized to test the hypothesis. The result showed that brand image deception has a negative impact on consumer purchasing intention. Also, attitude mediates the relationship between deceptive brand image and consumer purchase intention. The empirical finding confirms that deceptive marketing practices such as brand deception can change the attitude of consumers negatively toward brands and, therefore, affect the consumer purchase intentions. The findings suggest that honest brand marketing is beneficial in increasing the attitude toward the brand. This strategy will increase consumer purchase intentions.

A Study for Failure Examples Including with Engine Oil Leakage, Poor Contact by Fin Damage and Vaporizer Inferiority on LPG Automotive (LPG 자동차의 엔진오일누설, 핀 손상에 의한 접촉불량, 베이퍼라이저 내부불량으로 인한 고장사례연구)

  • IL Kwon, Lee;Chang Ho, Kook;Sung Hoon, Ham;Seung Yong, Lee;Jae Gang, Lee;Seung Min, Han; Woo Chan, Hwang;Dae Cheon, Jang;Chang Bae, You;Jeong Ho, Lee
    • Journal of the Korean Institute of Gas
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    • v.26 no.6
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    • pp.24-29
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    • 2022
  • This paper is a purpose to Analyze and study the failure examples for a engine oil leakage of camshaft bearing seal, poor contact by computer connector fin damage and vaporizer inferiority on LPG automotive. The first example, when the researcher disassembled the cylinder head of engine to establish the cause for oil leakage, he confirmed the engine oil leakage by damaged between the engine intake camshaft bearing and seal part. The second example, the connector fin of power source line that control the starting of a car supplied with engine computer. As a result, it found the fact that the engine operation stopped because of cutting of the power source by connector fin damage. The third example, it verified the engine incongruity phe cutting of the power source by connector fin damage. The third example, it verified the engine incongruity phenomenon as thd gas didn't flow the vaporizer by foreign substance deposit. Finally, it supplied a small quantity gas from vaporizer to mix. As the computer controlling mix opening condition supplied a air as opening signal, the air and fuel became rarefied state. it knew that the engine didn't produce prpper power. Therefore, a car have to throughtly inspect not in order to arise the failure symptoms.

The $10-{\mu}m$ Noth-Polar Bightening of Juptier: A Dynamical Phenomenon?

  • Kim, Sang Joon;Seo, Haingja
    • The Bulletin of The Korean Astronomical Society
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    • v.40 no.1
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    • pp.60.2-60.2
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    • 2015
  • Since its detection in 1980, the $8-{\mu}m$ north-polar brightening of $CH_4$ on Juptier has not moved from $180^{\circ}$ (SysIII) longitude. The $8-{\mu}m$ $CH_4$ brightening is mostly thermal and very similar to that of $13-{\mu}m$ $C_2H_2$ emissions, but the morphology of these hydrocarbon north-polar brightenings are very different from that of the $3-{\mu}m$ $H_3{^+}$ auroral oval suggesting a significantly different excitation process yet unknown heating mechanism. Recently, Kim et al. (submitted to Icarus, 2015) found that that the center of the $3-{\mu}m$ $CH_4$ northern bright spot is located at ${\sim}200^{\circ}$ (SysIII) longitude, which is ${\sim}20^{\circ}$ west from the center of the $8-{\mu}m$ north-polar bright spot, and it does not coincide with the $3-{\mu}m$ $H_3{^+}$ bright spot. They found significantly high temperatures (500 ~ 850K) from $CH_4$ rotational lines on the $3-{\mu}m$ bright spot above the $1-{\mu}bar$ pressure level, while we find cooler temperatures (<350K) over the the $8-{\mu}m$ spot. They also found that the upper states of the $3-{\mu}m$ $CH_4$ bands are mostly populated by non-thermal excitations, such as auroral particle precipitations and/or Joule heatings in contrast to the $8-{\mu}m$ thermal emission. This finding indicates that the $10-{\mu}m$ hydrocarbon brightening is confined to low altitudes below the $1-{\mu}bar$ level eliminating the long-suggested possibility of direct auroral bombardments while opening a new possibility of dynamical origin for the $10-{\mu}m$ brightening.

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Convergence analysis about volatility of the stock markets before and after the currency crisis - With a focus on Normal distribution, kurtosis, skewness (외환위기 전후 주식시장의 변동성에 관한 융복합 분석 - 정규분포, 첨도, 왜도를 중심으로)

  • Choi, Jeong-Il
    • Journal of Digital Convergence
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    • v.13 no.8
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    • pp.153-160
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    • 2015
  • The domestic stock market has been subjected to a major change since the September 1997 financial crisis. Foreign capital came repeat themselves in the stock market and bond market, foreign exchange market opening up domestic financial markets after the financial crisis. The domestic stock market has been most affected by domestic capital before the financial crisis. But it has been receiving an absolute influenced by foreign capital after the financial crisis. The purpose of this study is to analyze the trends in the two sections that look at any changes in the volatility of the KOSPI appears after the crisis. To this, obtained a daily weekly monthly normal distribution and kurtosis, skewness degree it should be analyze the tilt phenomenon and variability of the two intervals. This study also predict the future movement of the domestic stock market Based on this, look at the difference between the two sections. Analysis result, after the financial crisis change width has a reduction but direction of the KOSPI has appeared relatively distinct in the medium to long term. Based on this future market seems desirable the mid- to long-term investment looking for direction.

Factors of the Modernity of Belle Epoque and A study of phenomenon of Transitional Fashion (Belle Epoque의 의상 현대화의 요인과 과도기적 유행현상론 (1871~1914))

  • 김난공
    • Journal of the Korean Home Economics Association
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    • v.11 no.3
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    • pp.247-261
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    • 1973
  • In the past, what we call "fashion" was monopolized by only a small highly privileged group of individuals. To-day, we know that fashion field has become progressive democratization of taste not only in clothing, but in all expressions of contemporary living, from automobiles to refrigerators. So, we can find out how wonderful it is that our recent fashionable history was changed so fast. Whatever highly characteristic costume may be in the former, the way people dress was the reflection of their contemporary lives as well as their political status, economics, cultures, arts religions, so that a history of fashion is a history of life. Now, that categorical silhouettes make an exclusion across centuries of past history into the world of aesthetics, particularizes following ; symbolic voluminous toga of Roman authority, the religious but gorgeous Byzantine tunic, extravagant vertical bell-skirt of the Renaissance, the romantic Rococo style, the elegant crinoline and the bustle of the Cul de Paris of the nineteenth. It came true that women was intoxicated ostentations and elegances, since they had on ornamently costume which bear some relationship to the more formal Co-stesy, till the beginning of the twentieth. As Jonney Ironside said, "Nowadays, those exessive ornamentations and cumbersome design hardly belong to a civilization run by machines and in a hurry". These were once a sign of wealth and class ; at the beginning of the twentieth it was disappearing step by step. What is the reason\ulcorner At the end of the nineteenth, the emancipation of women, the movement of the Art Nouveau and the opening of the ready-made, have influenced on modern style, directly or indirectly. Finally, democratically popular costume was caused by fighting against the masculine prejudice excluded them from activities.hem from activities.

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A Study on the Digital Architectural Space's Characteristic of Expression Based on the Traditional Architecture Properties - Focused on the Immateriality Characteristics - (전통 건축 공간 특성으로 본 디지털 건축 공간의 표현특성에 관한 연구 - 비물질적 특성을 중심으로 -)

  • Lee, Joon-Ho
    • Korean Institute of Interior Design Journal
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    • v.23 no.5
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    • pp.51-57
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    • 2014
  • In the early 20st century, created distrust on the mechanistic and dualistic view based on the world of Descartes and Newton. As the features of this new science cannot be explained by the existing Western philosophy but can be explained by the thinking system immanent in the Oriental traditional thought, many scientists and philosophers are concentrating their interests on the Oriental philosophy. In addition, some have been making efforts to find solutions needed for a new paradigm from the thinking system of the Orient. A variety of discussions have also been raised in connection with architecture due to this philosophical change. It has now become possible to conduct free creative acts, staying away from physical limitations, including gravity by diversified simulations through a computer. This physical liberation in turn has caused new changes to the spatial concept of architecture, thereby granting the freedom of the expression that could not be even imagined before and opening a possibility of new architecture and space. At the same time, the digital space architecture actively accommodating this technology is generating a phenomenon that the existing physical and realistic things are rapidly being changed gradually to immaterial and unrealistic ones. This study has analyzed the properties of digital architectural space as the immateriality of our traditional architectural space. The results are as follows: It can be seen that the immaterial features exhibited in the digital architectural space and the traditional architectural one are not just interconnected with specific features, but they are correlated to all immaterial features. Thus, immateriality that are common in the traditional and digital architectural spaces is complementary organic, which is contained in the ambiguity of boundary between other spaces. It is regarded to the architecture as a living things in space diversity based on ideological similarities.