• Title/Summary/Keyword: 파랑환경

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HRV analysis Under Color Environment (생체 환경에서의 HRV 분석)

  • 정우석;정민영;양길태;양선호;김연희;송철규;김남균
    • Proceedings of the Korean Society for Emotion and Sensibility Conference
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    • 2001.05a
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    • pp.190-193
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    • 2001
  • 본 연구는 색채환경이 정상인의 심전도에 미치는 영향을 정량적으로 분석하여 색채 환경이 인체에 미치는 영향을 규명하고자 하였다. 피험자는 색맹을 가지고 있지 않고 인지기능에 장애가 없는 정상 성인 남, 여 50명을 대상으로 하였다. 색채환경의 제시는 암실에서 백색 광원에 채색 필터를 사용하여 제시하였다. 피검자는 6가지 색채 환경 안에서 심전도를 측정하였으며, HRV 분석을 하였다. HF/LF의 비를 비교 분석하여 본 결과, 남자는 녹색에서 색채 자극전보다 자극후가 HF/LF의 비가 0.508(p<0.07) 상승한 것을 볼 수 있었으며, 여자는 파랑색에서 색채자극전보다 자극후 HF/LF의 비가 0.677상승한 것을 볼 수 있었다. 이는 남자는 녹색에서 여자는 파랑색에서 더욱 편안함과 안락감을 느끼게 된다는 것을 의미한다. 따라서 본연구의 결과는 색채 환경이 인체에 미치는 영향을 규명함으로써 좀 더 편안한 색채 환경의 설계에 도움을 줄 것으로 기대된다.

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Numerical Analysis of Four Circular Columns in Square Array and Wave Interaction (파랑과 정사각형 배열의 원형 기둥 구조물의 상호작용 수치해석)

  • Song, Seongjin;Park, Sunho
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.23 no.5
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    • pp.558-565
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    • 2017
  • Accurate prediction of wave-structure interactions is important in the safety and design cost effectiveness of fixed and floating offshore structures exposed to extreme environmental conditions. In this study, regular waves and circular column structure interactions for four circular columns in regular waves are analyzed. To simulate 3D two-phase flow, open source computational fluid dynamics libraries, called OpenFOAM, were used. When the four circular columns are arranged in a square array, the interactions according to the incident slopes of the regular waves are analyzed. The wave run-up in the circular column surface was compared according to the slope of the incident wave. It was confirmed that high amplitude waves are generated between the circular columns due to the interaction between the circular column and the incident wave. It is expected that this analytical result will be used as the basic data of the study on the air gap due to the interaction between the structure and incident wave.

수로특성을 갖는 감조하천의 퇴적환경 수치모의

  • Baek, Dong-Jin;Kim, Gang-Min;Jeong, Dae-Deuk
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2018.05a
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    • pp.189-190
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    • 2018
  • 금회 연구대상인 아산만 내측에 위치한 배수로는 항만 건설로 인하여 인공적으로 생성된 감조하천의 성격을 띄고 있다. 이러한 인위적으로 설정된 배수로는 일반 하천에 비하여 유속이 크고 단순화된 유로로 인하여 퇴적 또는 침식우세 등의 극단적인 성격이 보인다. 따라서 이러한 퇴적환경 현황을 파악하기 위하여 금회 연구에서는 퇴적환경의 외력조건으로 작용하는 조석, 파랑, 그리고 하천 등의 영향을 분석하였으며, 이에 따라 유동 및 퇴적환경 현황을 재현하였다. 재현결과 협수로와 곡선부에서 침식이 기타 수로에서는 퇴적이 우세한 양상을 보이는 것으로 나타났다. 또한 이를 근거하여 차후 1, 5, 10년에 대한 장기간의 모델링을 수행하였으며, 이에 대한 결과 현재 배수로의 퇴적환경은 평형상태로 유지되는 것으로 판단된다. 그러나 배수로로는 대부분 간사지로 대기노출시간의 높은 편으로 지반의 고화현상이 발생하여 이에 대한 고려는 거의 불가하기 때문에 결과 보정 시 이를 고려한 결과해석이 필요할 것으로 판단된다.

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Coarse Grid Wave Hindcasting in the Yellow Sea Considering the Effect of Tide and Tidal Current (조석 및 조류 효과를 고려한 황해역 광역 파랑 수치모의 실험)

  • Chun, Hwusub;Ahn, Kyungmo
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.30 no.6
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    • pp.286-297
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    • 2018
  • In the present study, wave measurements at KOGA-W01 were analyzed and then the numerical wind waves simulations have been conducted to investigate the characteristics of wind waves in the Yellow sea. According to the present analysis, even though the location of the wave stations are close to the coastal region, the deep water waves are prevailed due to the short fetch length. Chun and Ahn's (2017a, b) numerical model has been extended to the Yellow Sea in this study. The effects of tide and tidal currents should be included in the model to accommodate the distinctive effect of large tidal range and tidal current in the Yellow Sea. The wave hindcasting results were compared with the wave measurements collected KOGA-W01 and Kyeockpo. The comparison shows the reasonable agreements between wave hindcastings and measured data, however the model significantly underestimate the wave period of swell waves from the south due to the narrow computational domain. Despite the poorly prediction in the significant wave period of swell waves which usually have small wave heights, the estimation of the extreme wave height and corresponding wave period shows good agreement with the measurement data.

Parametric Study on Effect of Floating Breakwater for Offshore Photovoltaic System in Waves (해상태양광 구조물용 부유식 방파제의 파랑저감성능 평가)

  • Kim, Hyun-Sung;Kim, Byoung Wan;Lee, Kangsu
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.35 no.2
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    • pp.109-117
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    • 2022
  • There has been an increasing number of studies on photovoltaic energy generation system in an offshore site with the largest energy generation efficiency, as increasing the researches and developments of renewable energies for use of offshore space and resources to replace existing fossil fuels and resolve environmental challenges. For installation and operation of floating photovoltaic systems in an offshore site with harsher environmental conditions, a stiffness of structural members comprising the total system must be reinforced to inland water spaces as dams, reservoirs etc., which have relatively weak condition. However, there are various limitations for the reinforcement of structural stiffness of the system, including producible size, total mass of the system, economic efficiency, etc. Thus, in this study, a floating breakwater is considered for reducing wave loads on the system and minimizing the reinforcement of the structural members. Wave reduction performances of floating breakwaters are evaluated, considering size and distance to the system. The wave loads on the system are evaluated using the higher-order boundary element method (HOBEM), considering the multi-body effect of buoys. Stresses on structural members are assessed by coupled analyses using the finite element method (FEM), considering the wave loads and hydrodynamic characteristics. As the maximum stresses on each of the cases are reviewed and compared, the effect of floating breakwater for floating photovoltaic system is checked, and it is confirmed that the size of breakwater has a significant effect on structural responses of the system.

The Effect of Sampling Rate on Statistical Properties of Extreme Wave (파랑자료의 sampling rate가 극한파의 통계에 미치는 영향)

  • Kim, Do Young
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.16 no.1
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    • pp.36-41
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    • 2013
  • In this paper time series wave data are simulated using wave spectrum with random phases of the wave signal. The simulated wave signals are used to study the effect of the sampling rate on the ocean wave characteristics. Effect of sampling rate on wave data which include extreme wave such as freak waves are examined and various wave characteristics including abnormality index (AI), kurtosis of wave profile and maximum wave height are examined. Various wave heights are decreased as the sampling rate decreases. The zero-th moment of the wave spectrum does not affect much on the sampling rate but the second moment are greately affected on the sampling rate. The error due to the sampling rate is decreases as the wave period increases. The error in significant wave height based on the wave spectrum $H_s$ is smaller than that on the time domain method $H_{1/3}$. AI index and kurtosis of wave profile do not deviate much from the exact date as long as the sampling rate is greater than 1 Hz. Ocean wave measurement with the sampling frequency higher than 1 Hz will result the error less than 5% in estimating the height of extreme waves.

Numerical Reproducibility of Wave Response for an Oscillating Wave Surge Converter Using Inverted Triangle Flap (역삼각형 플랩을 이용한 진자형 파력발전장치의 파랑응답에 대한 수치적 재현 가능성)

  • Kim, Tag-Gyeom;Kim, Do-Sam;Cho, Yong-Hwan;Lee, Kwang-Ho
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.33 no.5
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    • pp.203-216
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    • 2021
  • Analyzing various wave interactions with oscillating wave surge converters (OWSC) is essential because they must be operated efficiently under a wide range of wave conditions and designed to extract optimal wave energy. In the conceptual design and development stage of OWSC, numerical analysis can be a good alternative as a design tool. This study performed a numerical analysis on the behavioral characteristics of the inverted triangle flap against the incident waves using open source CFD to examine the essential behavioral attributes of OWSC. Specifically, the behavioral characteristics of the structure were studied by calculating the free water surface displacement and the flap rotation angle near the inverted triangular flap according to the change of the period under the regular wave conditions. By comparing and examining the numerical analysis results with the hydraulic model experiments, the validity of the analysis performed and the applicability in analyzing the wave-structure interactions related to OWSC was verified. The numerical analysis result confirmed that the hydrodynamic behavior characteristic due to the interactions of the wave and the inverted triangle flap was well reproduced.

The Relationship between Health and Mind-Body State According to Five Colors Preference (오색(五色)선호도에따른 건강과 심신상태의 관련성 연구)

  • Ahn, Ji-Hye
    • Journal of Naturopathy
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    • v.9 no.1
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    • pp.1-12
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    • 2020
  • Purposes: The purpose of this study was to investigate the relationship between five viscera, environmental and seasonal changes, and their preference for five colors. Methods: The survey performed using the Chinese medicine constitution and the five cardinal colors (Red, Blue, Yellow, White, Black) paper. Results: The blood types distributions were A, O, B, AB, and others in order. The proportion of smokers(75.6%) and non-drinkers(25.6%). Their color preferences were highest in blue and the lowest in black, but not significant. The proportion of the viscera was stomach(45.3%), liver-lung, intestine, and heart, and the tastes were spicy(48.8%), sweet, sour, salty, and bitter in order. Blue was the highest in all. kidneys(8.3%) preferred red and bitter yellow. The change in mind(35.7%) was highest, followed by scary thoughts and their color preferences varied. The most preferred place was 'cold place,' and 'dry place' was low. The most preferred seasons were 'autumn (38.6%), and the lowest was rainy. And their colors preference were blue. The respondents(89.9%) were normal, 5.7% hypertension and 4.4% hypotension. Healthy people preferred blue (91.8%) and hypertensives yellow with not significant. The diabetics preferred blue and red(p<.04). Conclusions: In the questionnaire survey on the health and physical abnormalities of Seoul citizens, various distributions found in each category, and most of them preferred blue. The results indicated that the questionnaire and the five- colored preference were a little interrelated. However, the results are to be primary data for research in this field.

Basic Data Analysis on Bio Block Placement for Sea grass Field in the Enclosed Bay (반폐쇄해역에서의 잘피장 조성 바이오블록 거치의 기초자료 분석)

  • Ahn, HyoJae;Lee, JoongWoo;Kang, SeokJin
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2015.07a
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    • pp.183-185
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    • 2015
  • 반폐쇄해역에서는 해수교환이 어렵고 육상에서 유입부하와 적조 등의 영향을 강하게 받기 때문에 항상 수질과 저질이 악화되기 쉬운 환경에 처해 있어서 이의 개선을 위한 일환으로 해양식물(잘피)의 서식환경을 복원하여 해양정화에 기여하기 위한 친환경적 접근이 필요하다. 다양한 해상환경조건하에서 잘피의 서식은 변화므로 특히, 파랑의 극한 외력여건에 견디는 친환경 잘피 지지구조물 기술개발이 우선되어야 한다. 본 연구는 잘피장 조성의 기반기술로 해양식생 지지용 바이오 블록을 개발하고 특히, 관광지 및 해양클러스터 단지로 대외적으로 알려져 있는 영도해역에서 영도구가 야심차게 준비해오고 있는 해상낚시터 인근해역에 적용할 수 있는 바이오 블록의 현장시범거치를 통해 잘피 등 해양식생을 유도하기 기반을 마련하기 위한 기초연구로 대상구역에서의 파랑해석과 식생 조성 후에 파랑의 반응특성을 수치모델을 통해 분석하고자 하였다. 계산 결과는 대상지역에 적용할 사면 피복재로 바이오 블록의 규격을 결정하는데 반영될 것이며 후속 연구에서 실제블록의 제작과 현장거치를 수행하고자 한다.

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