• Title/Summary/Keyword: 바람효과

Search Result 960, Processing Time 0.029 seconds

Variation and Structure of the Cold Water Around Ganjeol Point Off the Southeast Coast of Korea (하계 용승현상에 따른 간절곶 주변해역의 냉수역 구조와 변동)

  • Choo, Hyo-Sang
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.22 no.7
    • /
    • pp.836-845
    • /
    • 2016
  • The variation and structure of the cold water mass around Ganjeol Point during the summer of 2011 were studied using data from CTD observations and temperature monitoring buoys deployed at 20 stations off the southeast coast of Korea. There was a $-12^{\circ}C$ surface temperature difference between the cold water mass and normal water during the monitoring period. Variations in the isothermal lines for surface temperature along the coast showed that the seabed topography at Ganjeol Point played an important part in the distribution of water temperature. Cold water appeared when the wind components running parallel to the coast had positive values. The upwelling -response for temperature fluctuations was very sensitive to changes in wind direction. Vertical turbulent mixing due to the seabed topography at Ganjeol Point can reinforce the upwelling of cold bottom water. From wavelet analysis, coherent periods found to be 2-8 days during frequent upwelling events and phase differences for a decrease in water temperature with a SSW wind were 12-36 hours.

Nutrient Variations in the Jindong Bay during Summer by Ecosystem Modeling (해양생태계모델에 의한 하계 진동만의 영양염변동)

  • 김동선;홍철훈
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
    • /
    • v.8 no.2
    • /
    • pp.164-176
    • /
    • 2003
  • During summer, the DIN (dissolved inorganic nitrogen) and DIP (dissolved inorganic phosphate) observed in the Jindong Bay in the southern sea of Korea show much higher values in the inner area of the bay. In general, they have high values in the upper (0-1 m) and lower layers (8 m-bottom), but are relatively lower in the middle layer (1-8 m). These features in their distribution are examined using an ecosystem model with considering the wind, tidal current, horizontal gradient of water density and residual flow. The experiments were focused on how to influence nutrients associated with these conditions. In the experiment with tide-induced residual flow, the values of nutrients appeared lower than the observation, and were well corresponded to it when the effects of wind, tide-induced residual current and horizontal gradient of water density were additionally imposed. A statistical analysis identifies these results. This paper suggests that variation of nutrient in the Jindong Bay during summer should be seriously a(footed wind-driven current by the wind and density-driven current is induced by the horizontal gradient of water density as well as tidal current.

Wind Effect on Tidal Currents in the Neighborhood of Haeundae Beach (해운대 해수욕장 전면 해상의 조류에 미치는 바람효과)

  • Lee, Moon-Ock;Lee, Jong-Sup;Kim, Byeong-Kuk;Kim, Jong-Kyu
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.22 no.1
    • /
    • pp.34-46
    • /
    • 2010
  • We observed tidal currents throughout all four seasons in 2007 at a single station, located 1.6km off Haeundae Beach and compared these current data with wind data. The direction of seasonal wind represented a similarity between the winds at sea and on land but the speed of wind at sea was almost three times stronger than the wind on land. In addition, the wind at sea turned out to considerably affect on tidal currents, particularly from late summer to autumn. On the other hand, the thickness of Ekman Layer, indicating a limitation of wind influence, was estimated to be 31.8 m on average, suggesting that the entire water column is under the influence of wind. Therefore, we are required to consider the wind stress into the analysis of tidal currents for the prevention of the loss of sand from Haeundae Beach.

A Study on the Reduction in VR Cybersickness using an Interactive Wind System (Interactive Wind System을 이용한 VR 사이버 멀미 개선 연구)

  • Lim, Dojeon;Lee, Yewon;Cho, Yesol;Ryoo, Taedong;Han, Daseong
    • Journal of the Korea Computer Graphics Society
    • /
    • v.27 no.3
    • /
    • pp.43-53
    • /
    • 2021
  • This paper presents an interactive wind system that generates artificial winds in a virtual reality (VR) environment according to online user inputs from a steering wheel and an acceleration pedal. Our system is composed of a head-mounted display (HMD) and three electric fans to make the user sense touch from the winds blowing from three different directions in a racing car VR application. To evaluate the effectiveness of the winds for reducing VR cybersickness, we employ the simulator sickness questionnaire (SSQ), which is one of the most common measures for cybersickness. We conducted experiments on 13 subjects for the racing car contents first with the winds and then without them or vice versa. Our results showed that the VR contents with the artificial winds clearly reduce cybersickness while providing a positive user experience.

A Study on Evaluation Analysis of Wind Formation Function using KLAM_21 -The Case of Daegu City- (KLAM_21을 활용한 바람생성기능 평가분석 연구 -대구시를 대상으로-)

  • Ryu, Ji-Won;Jung, Eung-Ho;Kim, Dae-Wuk;Cha, Jae-Gyu;Son, Kyung-Su
    • Journal of the Korean Association of Geographic Information Studies
    • /
    • v.11 no.2
    • /
    • pp.85-92
    • /
    • 2008
  • This study, the one concerning the evaluation analysis of the function of the wind generation using KLAM_21, has examined closely how the wind really flows on the space of the city, working with the object of case location. In the first place, the cold air formed at upper stream of Sincheon river, a ravine of whole area of Gachang gully and an inclined plane of neighboring mountainous district, flows to the north and expands itself along the upper stream of the Sincheon river, and as the time passes, it is tending upwards in the change of the volume and height as well as of the velocity and direction, of the cold air. It was learned that this phenomenon has made it clear that the spatial features of this area give rise to very good condition in generating and flowing the cold air. Meanwhile, it has been shown that in the area of park in the Ap-mountain, the generation and flow of the cold air are much interrupted because of the overpass traversing the whole area of the park of Ap-mountain, the congested area of large-scaled apartments and the urban development activities constructing the building in the park, and the volume and height of the cold air has been grown very small. In conclusion, It has been learned that for maximization of the spatial effect of the wind corridor, the areas where the cold air is generated, flowed, accumulated, and maintained, have to be connected spatially, and this spatial connection has a close relation with spatial features of the area.

  • PDF

A Study on the Wind Ventilation Forest Planning Techniques for Improving the Urban Environment - A Case Study of Daejeon Metropolitan City - (도시환경 개선을 위한 바람길숲 조성 계획기법 개발 연구 - 대전광역시를 사례로 -)

  • Han, Bong-Ho;Park, Seok-Cheol;Park, Soo-Young
    • Journal of the Korean Institute of Landscape Architecture
    • /
    • v.51 no.2
    • /
    • pp.28-41
    • /
    • 2023
  • The objective of the study was to develop an Urban Windway Forest Creation Planning Technique for the Improvement of the Urban Environment using the case of Daejeon Metropolitan City. Through a spatial analysis of fine dust and heat waves, a basin zone, in which the concentration was relatively serious, was derived, and an area with the potential of cold air flow was selected as the target area for the windway forest development by analyzing the climate and winds in the relevant zone. Extreme fine dust areas included the areas of the Daejeon Industrial Complex Regeneration Business District in Daedeok-gu and Daedeok Techno Valley in Yuseong-gu. Heat wave areas included the areas of Daedeok industrial Complex in Moksang-dong, the Daejeon Industrial Complex Regeneration Business District in Daehwa-dong, and the high-density residential area in Ojeong-dong. As a result of measuring the wind speeds in Daejeon with an Automatic Weather System, the average wind speeds during the day and night were 0.1 to 1.7 m/s,, respectively. So, a plan of for a windway forest that smoothly induces the movement of cold air formed in outer forests at night is required. The fine dust/heat wave intensive management zones of Daejeon Metropolitan City were Daejeoncheon, Yudeungcheon, Gapcheon-Yudeungcheon, and Gapcheon. The windway forest formation plan case involved the old city center of Daejeon Metropolitan City among the four zones, the Gapcheon-Yudeungcheon area, in which the windway formation effect was presumed to be high. The Gapcheon-Yudeungcheon area is a downtown area that benefits from the cold and fresh air generated on Mt. Gyejok and Mt. Wuseong, which are outer forests. Accordingly, the windway forest was planned to spread the cold air to the city center by connecting the cold air generated in the Seosa-myeon forest of Mt. Gyejok and the Namsa-myeon forest of Mt. Wuseong through Gapcheon, Yudeungcheon, and street forests. After selecting the target area for the wind ventilation forest, a climate map and wind formation function evaluation map were prepared for the area, the status of variation wind profiles (night), the status of fine dust generation, and the surface temperature distribution status were grasped in detail. The wind ventilation forest planning concept and detailed target sites by type were identified through this. In addition, a detailed action plan was established according to the direction of creation and setting of the direction of creation for each type of wind ventilation forest.

The Relationship Between Empowerment and Innovative Behavior, and the Moderating Effect of Psychological Ownership in Small Musiness (중소기업 구성원의 임파워먼트와 혁신행동의 관계 및 심리적 주인의식의 조절효과)

  • Hong, Wan-Ki;Ahn, Kwan-Young
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
    • /
    • v.11 no.3
    • /
    • pp.145-155
    • /
    • 2016
  • The purpose of this study is to review the relationship between empowerment and innovative behavior, and the moderating effect of psychological ownership in small business. In order to verify and achieve the purposes mentioned above, questionnaire data are gathered and analysed from 315 employees in manufacturing enterprises of Kangwon-do province. Multiple regression and multiple hierarchical regression analysis were applied to test the proposed hypotheses: 1) the relationship between empowerment(meaning, autonomy, self-efficacy, impact) and innovative behavior(idea development, idea implementation), 2) the moderating effect of PO(psychological ownership for organization) on the relationship between empowerment and innovative behavior, 3) the moderating effect of PJ(psychological ownership for job) on the relationship between empowerment and innovative behavior. Empirical survey's findings are as follows; First, empowerment(meaning, autonomy, self-efficacy, impact) appeared to be positively related with innovative behavior(idea development, idea implementation). Second, there was no evidence of moderating effect of PO on the relationship between empowerment and innovative behavior. Third, meaning of work was more positively related with innovative behavior(idea development, idea implementation) in higher PJ group than in lower PJ group. Fourth, impact was more positively related with idea implementation in higher PJ group than in lower PJ group.

  • PDF

Development and Verification of a Rapid Refresh Wave Forecasting System (초단기 파랑예측시스템 구축 및 예측성능 검증)

  • Roh, Min;La, NaRy;Oh, SangMyeong;Kang, KiRyong;Chang, PilHun
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.32 no.5
    • /
    • pp.340-350
    • /
    • 2020
  • A rapid refresh wave forecasting system has been developed using the sea wind on the Korea Local Analysis and Prediction System. We carried out a numerical experiment for wind-wave interaction as an important parameter in determining the forecasting performance. The simulation results based on the seasons of with typhoon and without typhoon has been compared with the observation of the ocean data buoy to verify the forecasting performance. In case of without typhoon, there was an underestimate of overall forecasting tendency, and it confirmed that an increase in the wind-wave interaction parameter leads to a decrease in the underestimate tendency and root mean square error (RMSE). As a result of typhoon season by applying the experiment condition with minimum RMSE on without typhoon, the forecasting error has increased in comparison with the result without typhoon season. It means that the wave model has considered the influence of the wind forcing on a relatively weak period on without typhoon, therefore, it might be that the wave model has not sufficiently reflected the nonlinear effect and the wave energy dissipation due to the strong wind forcing.

Numerical Analysis of Wind Driven Current and Mesoscale Air Flow in Coastal Region with Land Topography (육상지형을 고려한 연안해역에서의 취송류에 관한 수치해석)

  • Lee, Seong-Dae;Kim, In-Ho;Hong, Chang-Bae
    • Proceedings of the Korea Water Resources Association Conference
    • /
    • 2006.05a
    • /
    • pp.1925-1930
    • /
    • 2006
  • A quasi depth-varying mathematical model for wind-generated circulation in coastal areas, expressed in terms of the depth-averaged horizontal velocity components and free surface elevation was validated and used to understand the diurnal circulation process. The wind velocity is considered as a dominant factor for driving the wind generated current. In this paper, three dimensional numerical experiments that included the land topography were used to investigate the mesoscale air flow over the coastal regions. The surface temperature of the inland was determined through the surface heat budget consideration with inclusion of a layer of vegetation. A series of numerical experiments were then carried out to investigate the diurnal response of the air flow and wind-generated circulation to various types of surface inhomogeneities.

  • PDF

A Numerical Modeling Study on the Seasonal Variability in the Gulf of Alaska (알라스카 만의 계절변화에 대한 수치모형 실험)

  • Bang, In-Kweon;Zygmunt Kowlik
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.6 no.3
    • /
    • pp.309-325
    • /
    • 1994
  • Ocean circulation in the Gulf of Alaska is remarkably constant throughout the year despite of being forced by one of the largest seasonal wind stresses in the world. To explain the small seasonal changes in the transport of Alaska Stream. a set of numerical models is employed. First a diagnostic approach is applied to reproduce circulation from the observed density structure. The results reveals the very small seasonal changes in the Alaska Stream transport. Next a series of the prognostic models is used: a barotropic model. a flat bottom baroclinic model, and baroclinic model with topography. These models reveal the influence of topography and baroclinicity on the ocean's response to the seasonal wind forcing. The intercomparisons of the various model results suggest that the seasonal response of the baroclinic ocean is primary barotropic and the resultant barotropic circulation is weakened by the scattering effect of the bottom topography.

  • PDF