• Title/Summary/Keyword: short wave

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The Analysis of Dynamic Behavior of Concrete Gravity Dam (중력식콘크리트댐의 동적거동분석)

  • 임정열;이종욱;오병현
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2001.09a
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    • pp.155-162
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    • 2001
  • In this study, it was performed that the seismic response analysis using long period earthquake wave and short period earthquake wave on dynamic behavior of concrete gravity dam. The results showed that if the same magnitude earthquake waves acted on concrete dam, the maximum displacement and stress at dam crest of long period wave(0funato wave) were about 30 % larger than those of short period wave(Hachinohe wave). And the response acceleration of dam crest was amplified about 5 times in long period earthquake wave and about 3 times in short period earthquake wave.

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Observation of Long and Short Wave Radiation During Summer Season in Daegu Area (대구지역의 하절기 장.단파복사 관측)

  • Oh, Ho-Yeop;Choi, Dong-Ho;Lee, Bu-Yong
    • 한국태양에너지학회:학술대회논문집
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    • 2012.03a
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    • pp.134-139
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    • 2012
  • This study observed downward long and short-wave radiant environment with selecting 4 areas which have different height in downtown and 1 suburban area to figure out the characteristic of radiant environment in each altitude. The purpose of this study is to collect the preliminary data for interpreting urban thermal environment in summer season by analyzing thermal characteristic of atmosphere in the upper of downtown. The results of this study are as follows. 1) The higher altitude has the lower temperature, and temperature difference was more huge in day time than night time. 2) The short wave radiation according to altitude was higher as altitude was high. 3) Generally, the higher altitude has the lower air temperature, and also the higher altitude has the lower downward long wave radiation by the atmospheric radiation. 4) The ratio short wave radiation of long wave radiation was lower as altitude was high. And the urbanization effect was higher as the ratio was low.

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Observation and Analysis of the Long and Short Wave Radiation According to Different Altitudes and Locations in Daegu During Summer (대구지역의 고도와 위치에 따른 하절기 장·단파복사 관측과 해석)

  • Choi, Dong-Ho;Lee, Bu-Yong;Oh, Ho-Yeop
    • Journal of the Korean Solar Energy Society
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    • v.32 no.4
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    • pp.71-81
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    • 2012
  • This study for the understanding of the radiation environment according to the altitude in urban area in the summer observes the long and short wave radiation environment at the 4 urban areas with different height and the 1 suburban area. The results of this study are as follows. (1) When the altitude was high, the more short wave radiation was observed. (2) As the altitude was high, the temperature of atmosphere got lower. And because of that the downward long wave radiation was also lower. This general trend was confirmed through the study. (3) Through the observation of long wave radiation, the upper atmosphere of suburban area had the atmosphere characteristic which the temperature was rising and decreasing faster. Therefore, the difference radiation characteristics between the urban and suburban area were confirmed. (4) The result of the ratio of short wave radiation to long wave radiation(short wave radiation/long wave radiation) according to the altitude and location, the value was increased when the distance was far from the artificiality structure or a heat source, and the urban effect became smaller. Thus, it is expected that the ratio will be an evaluation index for evaluating urbanization effect.

Comparison of Men's Hair Style Preference by Gender According to Occassion (상황에 따른 남성헤어스타일 선호도 성별 비교)

  • Kim, Mi-Jung;Park, Sook-Hyun
    • Fashion & Textile Research Journal
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    • v.11 no.1
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    • pp.156-165
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    • 2009
  • The purpose of this study was to compare men's hair style preference by gender according to occassion. Data were collected through a survey of 149 males and 175 females and analyzed by SPSS packages. The results of this study were as follows : 1) Male prefers to short, straight and black hair while female prefers to shot, nature wave and black hair. 2) Both male and female don't prefer to permanent and hair dyeing. 3) On the occasion of job interview, both male and female prefer to short, straight and black hair. On the occasion of blind date, male prefers to short, straight and black hair while female prefers to short, natural wave and natural brown hair. On the occasion of matchmaker meeting for marriage, male prefers to short, straight and black hair while female prefers to short, natural wave and dark brown hair. On the occasion of club party, male prefers to middle length, straight and black hair while female prefers middle length, natural wave and natural brown hair. On the occasion of leasure time, male prefers to short, straight and black hair while female prefers to short, natural wave and natural brown hair. And both male and female prefer to use hats for skin protection during outdoor leasure time.

Numerical studies on non-linearity of added resistance and ship motions of KVLCC2 in short and long waves

  • Hizir, Olgun;Kim, Mingyu;Turan, Osman;Day, Alexander;Incecik, Atilla;Lee, Yongwon
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.11 no.1
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    • pp.143-153
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    • 2019
  • In this study, numerical simulations for the prediction of added resistance for KVLCC2 with varying wave steepness are performed using a Computational Fluid Dynamics (CFD) method and a 3-D linear potential method, and then the non-linearities of added resistance and ship motions are investigated in regular short and long waves. Firstly, grid convergence tests in short and long waves are carried out to establish an optimal mesh system for CFD simulations. Secondly, numerical simulations are performed to predict ship added resistance and vertical motion responses in short and long waves and the results are verified using the available experimental data. Finally, the non-linearities of added resistance and ship motions with unsteady wave patterns in the time domain are investigated with the increase in wave steepness in both short and long waves. The present systematic study demonstrates that the numerical results have a reasonable agreement with the experimental data and emphasizes the non-linearity in the prediction of the added resistance and the ship motions with the increasing wave steepness in short and long waves.

Study on Characteristics of Radiation Environment in the Urban through the Field Observation in the Summer (하절기 도시의 장.단파 복사특성 관측)

  • Jung, Im-Soo;Choi, Dong-Ho;Lee, Bu-Yong
    • 한국태양에너지학회:학술대회논문집
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    • 2011.11a
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    • pp.105-110
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    • 2011
  • The objective of this study is to analyze the characteristic of radiation environment in the urban and rural through the field observation in the summer. The radiation balance was compared through the measurement of the shortwave radiation and long-wave radiation in the urban, sub-urban, and rural. The following conclusion could be obtained from this research. (1) In the results of observation including the rain-day, it was found that the short wave radiance in the urban is lower about 10% than the rural. (2) The upper part of atmosphere layers in the urban area absorb much short wave radiation energies compared with the rural relatively. It can increase the temperature of the upper part of atmosphere layers and the emittance of long wave radiation. (3) The ratio of the downward short wave radiation to the downward long wave radiation was 1.24 for the urban, 1.28 for sub-urban and1.35 for rural. It can be estimated that the atmosphere condition of the rural is better than that of other areas.

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Effects of Trim Conditions on Ship Resistance of KCS in Short Waves (단파장 영역에서 운항 자세가 KCS의 선체 저항에 미치는 영향)

  • Kim, Yeoun Joo;Lee, Sang Bong
    • Journal of the Society of Naval Architects of Korea
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    • v.54 no.3
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    • pp.258-266
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    • 2017
  • Numerical simulations of turbulent two phase flows around KCS have been performed to investigate effects of trim conditions on ship resistance of KCS in short waves by utilizing waves2foam. The wave lengths of LPP/2 and LPP/4 with 1m and 2m wave heights were imposed at inlet boundary. The resistance reduction at 2m trim by head and the increase of resistance at trims by stern were observed regardless of wave lengths and wave heights. The hull pressure on fore-and-aft rather than wave patterns around bulbous bows was mainly responsible for the total resistance coefficients of KCS in short waves. A phase diagram of contribution of hull pressure to the total resistance coefficients disclosed that the phase of representing the maximum resistance in time history played an important role in the effect of trim conditions on ship resistance of KCS in short waves.

Nonlinear Interaction of Directional Irregular Waves (비선형 간섭을 고려한 다방향 불규칙파의 해석)

  • 홍기용
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.7 no.3
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    • pp.209-218
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    • 1995
  • Nonlinear interaction between directional wave components is theoretically analyzed in deep water. The perturbed solution for an irregular wave is derived accurate up to the third order of the wave steepness and it is shown that the wave characteristics are modulated due to the nonlinear interaction. The convergence rate of the perturbed solution depends on not only wave steepness but also wavelength ratio between wave components. The long-wave component of the perturbed solution converges rapidly. while the short-wave solution converges slowly or diverges. The short wave properties in a broad-band wave spectrum cannot accurately be obtained by the conventional wave-mode method because it fails to properly describe the modulation of short-wave frequency caused by the nonlinear interaction with much longer wave.

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Observation and Analysis of Long and Short-wave Radiation According to Types of Summer Shelters (하계 그늘쉼터 유형별 장·단파복사 관측과 해석)

  • Baek, Chang-Hyeon;Choi, Dong-Ho;Lee, Bu-Yong;Lee, In-Gyu
    • Journal of the Korean Solar Energy Society
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    • v.39 no.6
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    • pp.127-135
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    • 2019
  • In this study, we analyzed the relationship between five factors: long-wave radiation, short-wave radiation, cloudiness, SVF and summer shelters. In the previous study, we recognized the correlation between single building SVF and long-wave radiation. Furthermore, this study attempted to confirm the relationship at the summer shelter with high solar radiation blocking rate. The observations are as follows. ① Cooling in summer shelters was not the effect of temperature but the effect of radiation reduction due to short-wave radiation shielding. ② In the case of the canopy tent with low heat capacity, the long-wave radiation was observed to be 16.7% higher per hour than the comparison control point due to the increase in surface temperature. ③ The long-wave radiation increase rate was different according to SVF, but showed very similar pattern according to the material characteristics of the summer shelters. ④ Passive Cooling effect on the type of summer shelters are determined by the size of the total long and short-wave radiation at that point.

Study on the analysis of impulse test wave in the short coil (layer)of transformer winding (변압기 권선(층간)단락시의 충격파시험파형분석에 관한 연구)

  • 박민호
    • 전기의세계
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    • v.25 no.5
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    • pp.75-78
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    • 1976
  • The most difficult problem encountered in impulse test of transformer is the determination of exact fauly for coil layer short. This paper is to establish one of improved standards in the above case by means of wave form analysis, based on the equivalent circuits and experimental investigation. During the fault occurs, the local oscillation in fault circuit is applicable where as the reflection wave is utilized to the main circuit. The result current wave form at neutral impeadance point is similar to the wave form by impulse test and has the singular wave form respectively.

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