• Title/Summary/Keyword: 파도

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A Study on the Fate of Futurism: Russian Futurism in the 20th Century and Korean 'Futurism' in the 21th Century (미래파 현상의 운명에 관한 소고: 20세기 러시아 미래파와 21세기 한국 '미래파'를 중심으로)

  • Park, Sun-Yung
    • Cross-Cultural Studies
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    • v.44
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    • pp.239-281
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    • 2016
  • This article explores the fate of futurism not only by tracing the entire process from the birth and decline of Russian futurism in the early 20th century and the so-called "Korean futurism" in the early 21st century, but also by delving into how their characteristics were shaped. In the first chapter, we investigate four groups of Russian futurism - Ego-Futurism, Cubo-Futurism, Tsentrifuga, and the Mezzanine of poetry, which were born in the age of utopianism before the Revolution. In the opera Victory Over the Sun, which was the culmination of the Zaum project of Cubo-futurists, we can find the initial shortcomings at the levels of language (Kruchenykh), music (Matyushin) and decoration and costume design (Malevich). In the second chapter, we examine chronologically how the term 'futurism' appeared in Korean literature history. In Korea, the term 'futurism' was born following the naming and classification of critic Kwon Heok-Woong, not by the voluntary manifestation of experimental poets such as Hwang Byong-Seung, thus this specific situation provoked stormy polemics between critics for futurism and critics against futurism in the Korean literary world. These polemics on futurist poetics have led to considerations of the relation of criticism to poetry.

Elastic Wave Characteristics According to Cementation of Dissolved Salt (용해된 소금의 고결화에 따른 탄성파 특성)

  • Eom, Yong-Hun;Truong, Q. Hung;Byun, Yong-Hoon;Lee, Jong-Sub
    • Journal of the Korean Geotechnical Society
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    • v.25 no.5
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    • pp.75-86
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    • 2009
  • Salt, one of the most common soluble materials in engineering soil, may have an effect on mechanical behaviors of soils under its cementation process. In order to investigate this natural phenomenon, non-soluble material by using glass beads is mixed with salt electrolyte and cemented by using oven to evaporate water. Three different sizes of glass bead particles, 0.26, 0.5, and 1.29 mm, with different salt concentration, 0, 0.1, 0.2, 0.5, 1.0, and 2.0M, are explored by using P- and S-waves, excited by bender elements and piezo disk elemets, respectively. The velocities of the P-wave and S-wave of the particulate medium cemented by salt show three stages with the degree of saturation: 1) S-wave velocities increase while P-wave velocities reduce with degree of saturation changing from 100% to 90%; 2) Both velocities are stable with degree of saturation varying from 90% to 10%; 3) The velocities change enormously when the specimens are nearly dry with degree of saturation from 10% to 0%. Besides, the resonance frequencies of S-wave show similar stages to the S-wave velocities. This study demonstrates meaningful trends of elastic wave characteristics of geo-materials according to the cementation of dissolved salt.

Field Elastic Wave and Electrical Resistivity Penetrometer for Evaluation of Elastic Moduli and Void Ratio (탄성계수 및 간극비 평가를 위한 현장 관입형 탄성파 및 전기비저항 프로브)

  • Yoon, Hyung-Koo;Kim, Dong-Hee;Lee, Woojin;Lee, Jong-Sub
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.30 no.2C
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    • pp.85-93
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    • 2010
  • The shear stiffness has become an important design parameter to understand the soil behavior. In particular, the elastic moduli and void ratio has been considered as important parameters for the design of the geotechnical structures. The objective of this paper is the development of the penetration type Field Velocity and Resistivity Probe (FVRP) which is able to assess the elastic moduli and void ratio based on the elastic wave velocities and electrical resistivity. The elastic waves including the compressional and shear wave are measured by piezo disk elements and bender elements. And the electrical resistivity is measured by the resistivity probe, which is manufactured and installed at the tip of the FVRP. The penetration tests are carried out in calibration chamber and field. In the laboratory calibration chamber test, after the sand-clay slurry mixtures are prepared and consolidated. The FVRP is progressively penetrated and the data are measured at each 1 cm. The field experiment is also carried out in the southern part of Korea Peninsular. Data gathering is performed in the depth of 6~20 m at each 10 cm. The elastic moduli and void ratio are estimated based on the analytical and empirical solutions by using the elastic wave velocities and electrical resistivity measured in the chamber and field. The void ratios based on the elastic wave velocities and the electrical resistivity are similar to the volume based void ratio. This study suggests that the FVRP, which evaluates the elastic wave velocities and the electrical resistivity, may be a useful instrument for assessing the elastic moduli and void ratio in soft soils.

Comparison of Rice Growth and Yield in Different Direct Seeding Methods (벼 직파 유형별 생육 및 수량 비교 연구)

  • Park, K.H.;Park, S.T.
    • Journal of Practical Agriculture & Fisheries Research
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    • v.19 no.1
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    • pp.119-128
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    • 2017
  • The field trial was performed to evaluate the rice growth and yield in different direct seeding methods. The required time for seed emergence was for 8~ 9days in the tested direct seeding methods and there was high in seedling establishment according to wet hill-seeding with iron-coated seeds> wet hill-seeding with soil coverage>water seeding with iron-coated seeds and water seeding with pregerminated seeds as the conventional treatment. The rice plant height was taller in wet hill-seeding methods than that of water seeding with broadcasting method but there was not significant difference in terms of statistical analysis at 75day after seeding except the water seeding with pregerminated seeds. The growth of tiller number in the rice plant was highest in water seeding with iron-coated seeds. The milled rice yield was highest in water seeding with iron-coated seed being with 6.4t/ha and percentage of head rice was the highest in wet hill-seeding and water seeding with iron-coated seeds.

저주파 및 고주파 구동 대기압 플라즈마 젯의 특성 비교

  • Gwon, Yang-Won;Baek, Eun-Jeong;Eom, In-Seop;Jo, Hye-Min;Kim, Seon-Ja;Jeong, Tae-Hun
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.194.2-194.2
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    • 2016
  • 저주파 (수십 kHz)와 고주파 (13.56 MHz)로 구동되는 대기압 플라즈마 젯을 발생시키고, 인가전압 (혹은 인가전력)과 기체 유량에 따른 대기압 플라즈마의 특성을 비교하였다. 고주파에서 발생된 플라즈마는 저주파의 경우보다 안정적이었으며, 인가전압 (혹은 인가전력)이 증가함에 따라 플라즈마 기체온도는 상승하였고, 고주파 젯의 기체온도는 저주파 젯 보다 높았으나 330 K이하인 것을 확인하였다. Optical Emission Spectroscopy (OES)를 이용하여 저주파와 고주파의 광 방출 특성을 측정하였다. 저주파에서는 $N_2{^+}$ (391.4 nm)의 intensity 증가가 두드러지게 나타났지만 고주파 젯에서는 $N_2$, $N_2{^+}$의 intensity는 감소하였으며, OH, NO, $H_{\alpha}$, O와 같은 활성 산소 종 (Reactive Oxygen Species)이 저주파 젯 보다 높게 측정되었다. Boltzmann plot method를 이용한 분석을 통해 저주파와 고주파 영역에서의 플라즈마 전자 여기 온도를 측정하였다. 또한 자외선 흡수분광법을 이용하여 플라즈마-액체 계면에서의 OH이 입자밀도를 측정하여 OES방법으로 측정한 OH 밀도와 비교하였다. 그리고 화학적 측정법 (terephtalic acid solution)을 이용하여 액체 내의 OH의 농도를 측정하였다.

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MRSF-PWM Method for Acoustic Noise Reduction of Traction Motor Drive Systems (견인전동기 구동시스템의 소음 저감을 위한 MRSF-PWM 방식)

  • 홍순찬;서영민
    • The Transactions of the Korean Institute of Power Electronics
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    • v.7 no.3
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    • pp.262-271
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    • 2002
  • In PWM inverters used in traction motor drive systems, the switching frequency is restricted by their large power capacity and thus the electromagnetic acoustic noise is generated. To reduce such an audible noise, the new MRSF-PWM(Modified Random Switching Frequency PWM) method is proposed. In the Proposed MRSF-PWM method, both triangular wave and sawtooth wave are used together as carrier waves for harmonic diffusion and reference wave is generated by injecting 3rd harmonic into the stone wave to expand the linear control region of output voltages. To verify the validity of the proposed MRSF-PWM method, computer simulations are carried out. And the results show that the MRSF-PWM method is more excellent than other RPWM methods in the aspects of both linearity and harmonic diffusion md more effective than SPWM(Sinusoidal PWM) method for the reduction of an audible noise.

Measured Effect of Shock Wave on the Stability Limits of Supersonic Hydrogen-Air Flames (충격파가 초음속 수소-공기 화염의 안정한계에 미치는 영향)

  • Hwanil Huh
    • Journal of the Korean Society of Propulsion Engineers
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    • v.3 no.1
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    • pp.86-94
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    • 1999
  • Measured shock wave effects were investigated by changing shock strength and position with particular emphasis on the stability limits of hydrogen-air jet flames. For this purpose, a supersonic nonpremixed, jet-like flame was stabilized along the axis of a Mach 2.5 wind tunnel, and wedges were mounted on the sidewall in order to interact oblique shock waves with the flame. This experiment was the first reacting flow experiment interacting with shock waves. Schilieren visualization pictures, wall static pressures, and flame stability limits were measured and compared to corresponding flames without shock-flame interaction. Substantial improvements in the flame stability limits were achieved by properly interacting the shock waves with the flameholding recirculation zone. The reason for the significant improvement in flame stability limits is believed to be the adverse pressure gradient caused by the shock, which can elongate the recirculation zone.

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Development of Multi-channel Simultaneous Laser Shock Sensing System for Linear Explosive-induced Pyroshock Propagation Prediction (선형화약 파이로 충격파 전파 예측을 위한 다채널 동시 레이저 충격파 센싱 시스템 개발)

  • Jang, Jae Kyeong;Abbas, Haider;Lee, Jung Ruyl
    • Journal of the Korean Society of Propulsion Engineers
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    • v.19 no.5
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    • pp.46-51
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    • 2015
  • Multi-channel DAQ system was developed to predict propagation characteristic of the shock wave generated by linear explosive. The system can generate shock wave from 1000 points per second using a pulsed laser and simultaneously obtain the shock wave signals using 15 chanel contact sensor. The system is expected to pridict the propagation characteristics of various linear explosive-induced pyroshock because it can be used with a user-defined time delay that corresponds to detonation speed of the linear explosive.

A Research of Power Factor Improvement using Phase Control of Active Harmonic Filter (고조파저감설비 위상제어를 통한 역률 향상에 관한 연구)

  • Choi, Won-kyu;Lee, Hwan;Jung, No-Geon;Jeon, Yeon-Ju;Kwon, Kyoung-min;Kim, Jae-Moon
    • Proceedings of the KIEE Conference
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    • 2015.07a
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    • pp.1609-1610
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    • 2015
  • 국내 철도 변전소의 부하전력은 부하인 철도차량의 부하특성에 의해 고조파와 역률이 매우 좋지 못한 실정이다. 이러한 이유에서 철도변전소에는 고조파를 보상하기위한 고조파 저감설비와 역률을 개선시키기 위한 역률보상용 콘덴서와 같은 전력품질개선설비(FACTs) 들이 설치되고 있다. 본 논문에서는 이러한 철도차량 부하의 차량별 고조파 특성을 살펴보고, 이를 효과적으로 제어할 수 있는 방법을 제안하였다. 제안된 알고리즘은 고조파저감설비의 위상제어를 통한 역률 향상을 도모하기 위한 것으로 일반적인 밴드패스 필터를 사용한 고조파 전류성분 검출에 따른 제어방식과 달리 고조파 전류에 대한 Lyapunov 안정도에 기반을 둔 제어방식을 적용하여 빠른 전류제어 동특성을 같도록 제안하였고 시뮬레이션과 실 부하 계통에 설치하여 운용함으로 그 타당성을 입증하였다.

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Wave Damping Rate Over Multi-layer Permeable Bed of Finite Depth (깊이가 유한한 다중 투수층 위에서의 파의 감쇠율)

  • Suh, Kyung-Duck;Do, Ki-Deok
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.21 no.2
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    • pp.127-135
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    • 2009
  • Reid and Kajiura(1957) has studied on the wave damping rate over a permeable bed of infinite depth. In this study, wave damping rate over a permeable bed of finite depth is derived by linear wave theory. It is then extended to derive wave damping rates over a double or triple layer, each of which consist of different material. Applying the wave damping rate to the mild slope equation, the wave transmission coefficient over a permeable bed has been calculated. The model has been certificated by comparing with the result of Flaten and Rygg(1991)'s integral equation method in the case of a single-layer bed.