• Title/Summary/Keyword: Wave tendency

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An Analysis of Runoff Characteristics at Creeks (소하천 유역의 유출변화 특성분석)

  • Jung, Jae-Wook;Yoon, Sei-Eui
    • Journal of the Korean Society of Hazard Mitigation
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    • v.1 no.2 s.2
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    • pp.75-83
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    • 2001
  • In this study, the maintenance problems were investigated through checking the creeks which were improved by close-to-nature river improvement technique. The characteristics of flow were measured at Changsa Creek in Suwon city. The computational results of numerical model with kinematic wave theory was evaluated through observation data about precipitation, velocity, and flow depth. Furthermore, SCS, Clark, and RRL models were compared to the actual observations. As a result, the kinematic wave theory's calculated peak time of discharge concentration occurred little earlier than the actual observation, but the tendency of hydrograph coincided with observation.

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A Simulation for Indentifying Influence of The VVT Effect on The SI Engine Performance Using WAVE (WAVE 를 이용한 VVT 효과가 SI 엔진성능에 미치는 영향에 관한 시뮬레이션)

  • Lim, Ock-Taeck;Kim, Dae-Ho;Dutta, Diganta;Tsogtjargal, G.
    • Proceedings of the KSME Conference
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    • 2008.11b
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    • pp.3032-3037
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    • 2008
  • Variable Valve Timing (VVT) system can be used to improve fuel economy, performance and emissions. This study is identified the effect of VVT in terms of wide open throttle torque, Residual gas fraction, volume efficiency. Engine cycle simulations are performed on 2.0L DOHC in-line 4-cylinder SI engine by using WAVE of Ricardo. Results of the simulations had good agreement with WOT torque experimental data, and helped to predict the tendency of performance as the valve timings change. WOT torque was higher when intake valves were closed early for low rpm and late for high rpm.

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Tendency of Well-Being in Hair Styles (헤어스타일의 웰빙 경향)

  • Ha, Gyeong-Yeon
    • Journal of the Korean Society of Fashion and Beauty
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    • v.2 no.3 s.3
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    • pp.11-18
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    • 2004
  • The purpose of this study was to review the origin and background of well-being, the emerging well-being culture, and the phenomenon and features of the hair beauty affected by it. For this purpose, the researcher reviewed dissertations written between 199a and 2002, copies of the beauty journal Short Hair published between 2002 and 2003, beauty newspapers published between March, 2003 and June, 2004, and relevant Internet sites. When we review the well-being hair style tendency, we may be reminded of a light shaggy cut style with a thick wave volume or a natural wave highlighted, or a natural style with a natural color rendered by the braid technique. The well-being hair styles may be inspired by such natural images as the earth, sand, rock, wind, feather and flowers, while using cut, permanent wave or coloring technique for the hairs, in order to create new hair styles. The goal is to make men in contact with the nature. Meanwhile, as people are more concerned about diverse hair textures, natural and healthy hairs, they want their hairs to look comfortable and active rather than luxurious. The well-being cut styles may be categorized into cut style highlighting healthy hairs with a Bobos luxury and soft and light stroke cut reminiscent of a Bohemian freedom. The well-being permanent style may be divided into thick wave, natural wave, and the permanent style using a strong wave to make hairs look bloated. The hair colors reminding us of some natural images are used to highlight a well-being image. In addition, the concept of well-being pursuing a happy and healthy life has been being introduced into the permanent wave material liquids; such liquids made from natural materials, fruits or herbs increase, while environmental-friendly liquids or materials are used more for healthy hairs. The reason why the well-being culture influences hair styles importantly may be that people's desire of healthy body and mind and a comfortable life is reflected in hair styles. In conclusion, as the hair styles or an index for a new cultural current in our modern age are influenced by the well-being phenomenon, more and more people will put priority on healthy hairs. So, it is deemed necessary to apply the well-being hair styles appropriately to render satisfactory hair styles.

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Heating & Drying Characteristics of Coating Layer by Induction Heating and Short-wave Infrared Heating (유도가열 및 근적외선 가열방법에 의한 표면처리 강판 도포층의 가열 및 건조 특성)

  • Kim T. S.;Yang J. W.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2004.08a
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    • pp.249-257
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    • 2004
  • Drying and curing characteristics of PCM resins using the induction heater and short-wave infrared emitter module was studied to develop a compact oven system for the high speed CCL and post-treatment equipment. Drying of the polyester resins using the induction heater and infrared heater showed that the blistering tendency of polyester resin coating increased regardless of additives and colors of resins as the heating rate and/or dry film thickness increased. The blistering of polyester resin coating layer occurred when the heating speed was over than $25^{\circ}C/sec$ for the dry film thickness of $19\~20um$, which is the typical thickness of finish coating in CCL. So did it when the heating speed was over than $40^{\circ}C/sec$ for the dry film thickness over than 10 um. The heating efficiency of paint coated steels by the infrared heating was strongly dependent on the colors of paint coating and generally increased for the dark surface and/or coating. But the faster drying of the PCM resin coatings increased the blistering tendency of coating layer. The blistering limit for the typical finish coating by the infrared heating was estimated as the heating rate slower than $20^{\circ}C/sec$ regardless of colors of PCM resins.

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An Analysis of Statistical Characteristics of Nonlinear Ocean Waves (비선형 해양파의 통계적 특성에 대한 해석)

  • Kim, Do-Young
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.13 no.2
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    • pp.112-120
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    • 2010
  • In this paper time series wave data measured continuously for 24 hours during a storm in Yura Sea Area are used to investigate statistical characteristics of nonlinear waves. The exceedance probability of wave height is compared using the Rayleigh distribution and the Edgeworth-Rayleigh (ER) distribution. Wave data which show stationary state for 10 hours contain 4600 waves approximately. The Gram-Chalier distribution fits the probability of wave elevation better than the Gaussian distribution. The Rayleigh ($H_{rms}$) distribution follows the exceedance probability of wave height in general and predicts the probability of freak waves well. The ER distribution overpredicts the exceedance probability of wave heights and the occurrence of freak waves. If wave data measured for 30 minute period which contains 250 waves are used, the ER distribution can predict the occurrence probability of freak waves well. But it overpredicts the probability of overall wave height If no freak wave occurs, the Rayleigh ($H_{rms}$) distribution agrees well with wave height distribution for the most of wave height ranges. The wave height distribution of freak waves of which height are less than 10 m shows similar tendency compared with freak waves greater than 10 m. The value of $H_{max}/H_{1/3}$ is related to the kurtosis of wave elevation. It seems that there exists threshold value of the kurtosis for the occurrence of freak waves.

A Study on MsS Guided Wave Scattering from Defects (MsS Guided Wave를 이용한 결함 신호의 분석에 관한 연구)

  • Choi, Boo-Il;Cho, Youn-Ho;Lee, Joon-Hyun;Shin, Dong-Chul
    • Journal of the Korean Society for Nondestructive Testing
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    • v.29 no.5
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    • pp.442-449
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    • 2009
  • An investigation has been made on the relationship between characteristics of torsional mode signal in MsS and SH mode signal in BEM modeling for the defect of stainless steel pipe. In order to compare torsional mode signal with SH mode signal of defect in stainless steel pipe, specimens were made by changing size of depth and width along to circumferential direction 360 degrees. All the defects was detected by torsional mode signal of MsS, especially according to the change of depth size, amplitude of signal was changed. But width change for the circumferential defects has no certain tendency. SH mode signal of BEM modeling shows similar results with torsional mode, with change makes amplitude variation of signal. In this paper, the characteristics of torsional mode and SH mode signals were found. It is possible to predict the circumferential defects for the pipe by SH mode modeling.

Effect of Acetylcholine on Electrical Activity of Cat Stomach (자율신경계에 작용하는 약물이 위장 전기도에 미치는 영향)

  • Kim, Myung-Suk;Park, Hyoung-Jin;Bai, Sun-Ho;Choi, Hyun;Kim, Chul
    • The Korean Journal of Physiology
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    • v.14 no.2
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    • pp.21-28
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    • 1980
  • In order to investigate the effect of cholinergic substance on the electrical and the mechanical activities of the stomach muscle, 10 isolated cat stomachs were studied. At various sites of a stomach muscle preparation, the electrical activity was monopolarly recorded by using capillary electrodes containing chlorided silver wires, and the isometric contractile activity was recorded simultaneously at the terminal portion of the antrum in Krebs solution$(36^{\circ}C)$ which was aerated with a gas mixture consisting of 95% $O_2$ and 5% $CO_2$. The recording of these activities were performed before (control period) and after acetylcholine$(10^{-5}M)$ and atropine $(10^{-6}M)$ administrations serially. Following results were obtained: 1) The mean frequency of the slow wave was $4.36{\pm}0.22\;cycles/min$ at all the various sites of the cat stomach. The slow wave was propagated caudad in sequence and its velosity of propagation increased as the slow wave approached the pylorus in normal Krebs solution. 2) After acetylcholine administration, the frequency of the slow wave increased transiently and the increase of slow wave frequency was followed by the isometric contraction of antral muscle in association with the second potential which succeeded the slow wave. 3) By atropine administration, the stimulatory effect of acetylcholine on the antral muscle contraction was abolished completely, and the frequency of the slow wave decreased significantly compared with that of the control period, which tendency was more prominent in the antrum. The above results suggest that the transient increase in the frequency of gastric slow wave by acetylcholine may have some influence upon the contraction mechanism of the cat antral muscle.

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Temporal and Spatial Variations in the Wave Energy Potential of the East Coastal Seas of Korea (동해 연안 파력 부존량의 시간적 및 공간적인 변동 양상)

  • Jeong, Weon Mu;Cho, Hongyeon;Oh, Sang Ho;Kim, Sang Ik
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.25 no.5
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    • pp.311-316
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    • 2013
  • In this study, the wave energy potential (WEP) was evaluated using the wave data measured at nine stations along the Korean east coast and compared with the results of previous studies. Along the Korean east coast, seasonal variations in the WEP were around 6.4 kW/m in winter and 1.2 kW/m in summer, greater than spatial variations of 2.5~4.3 kW/m. In most stations, the wave power during June to July were shown to be smallest. The estimated annual average WEP was greatest in the Mukho and Jukbyeon stations located in the middle of the Korean east coast at around 4.3 kW/m, and smallest in the Jinha station at around 2.5 kW/m. The results found using the previous hindcast data showed WEP having a tendency to decrease from south to north. However, in this study, the WEP showed a tendency of being greatest in the middle of the Korean east coast and decreasing in both north and south directions.

A clinical study of atopic dermatitis patients as measured by Pulse diagnostic apparatus (맥진기(脈診器)를 이용한 아토피 피부염 환자의 임상적 고찰)

  • Shin, Yoon-Jin;Kim, Yoon-Bum;Yoon, Sang-Heub
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.21 no.2
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    • pp.112-119
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    • 2008
  • Objective : The quantification of pulse diagnosis is an important subject utilizing as a modernization of Oriental medical diagnosis and as a basic data for collaborative access between East and West Medicine. This study was to observe the tendency of pulse diagnosis in atopic dermatitis patients as measured by pulse diagnostic apparatus. Methods : We did pulse diagnostic test about 11 new outpatients who had visited the department of ophthalmology, otolaryngology, dermatology in Kyunghee oriental medical center from March 1, 2007 to October 31, 2007 and had atopic dermatitis. Results : The results were as follows. 1. Among the 11 outpatients, the total number of male patients were 5 and female patients were 6, and the age distribution, the most frequently visited age groups were 10-19 years old and 20-29 years old(each 4 patients). 2. The most common period of onset to first examination were 3 years${\leq}$ (7 patients). 3. There were 8 patients who had emphasized T-wave. 4. There were 7 patients who had repeated pulse wave pattern. Conclusion : In 11 cases who had atopic dermatitis, 8 patients had emphasized T-wave and 7 patients had repeated pulse wave pattern.

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Spiral Arm Features in Disk Galaxies: A Density-Wave Theory

  • Kim, Yonghwi;Ho, Luis C.
    • The Bulletin of The Korean Astronomical Society
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    • v.44 no.1
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    • pp.34.2-34.2
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    • 2019
  • Several observational results show a tighter pitch angle at wavelengths of optical and near-infrared than those that are associated with star formation, which is in agreement with the prediction of the density wave theory. In my recent numerical studies, the dependence of the shock positions relative to the potential minima is due to the tendency that stronger shocks form farther downstream. This causes a systematic variation of the perpendicular Mach number, with radius and makes the pitch angle of the gaseous arms smaller than that of the stellar arms, which supports the prediction of the density-wave theory, independently. However, some observations still give controversial results which show similar pitch angles at wavelengths, and there is no statistical study comparing observations and numerical models directly. By analyzing optical image of disk galaxies in the Carnegie-Irvine Galaxy Survey (CGS), I measured the physical values of stellar and gaseous arms such as their strength, length, and pitch angles. For direct comparison with numerical results, I analyzed more than 30 additional numerical models with varying the initial parameters in model galaxies. In this talk, I will present results both of observational and numerical samples and discuss the physical properties of spiral structures based on the density-wave theory.

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