• Title/Summary/Keyword: swell

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A Study on the Predictability of Eastern Winter Storm Waves Using Operational Wind Forecasts of KMA (기상청 현업 예보 바람자료를 이용한 동해안 동계 파랑 예측 재현도 연구)

  • Do, Kideok;Kim, Jinah
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.30 no.5
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    • pp.223-233
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    • 2018
  • The predictability of winter storm waves using KMA's operational wind forecasts has been studied to predict wind waves and swells in the East coast of Korea using SWAN. The nested model were employed along the East coast of Korea to simulate the wave transformation in the coastal area and wave dissipation term of whitecapping is optimized to improve swell prediction accuracy. In this study, KMA's operational meteorological models (RDAPS and LDAPS) are used as input wind fields. In order to evaluate model accuracy, we also simulate wind waves and swells using ECMWF reanalysis and KIOST WRF wind and they are compared with the KMA's operational wave model and the wave measurement data on the offshore and onshore stations. As a result, it has the lowest RMSE and the highest correlation coefficient in the onshore when the input wind fields are KMA's operational meteorological forecasts. In the offshore, all of the simulate results shows good agreements with similar error statistics. It means that it is very feasible to use SWAN model with the modified whitecapping factor and KMA's operational meteorological forecasts for predicting the wind waves and swells in the East coast of Korea.

An Analysis on Inundation Characteristics of Urban Watershed according to Variation in Return Period of Design Rainfall (설계 강우량의 재현빈도 변화에 따른 도시유역의 침수특성 분석)

  • Park, InHyeok;Ha, SungRyong
    • Journal of Wetlands Research
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    • v.15 no.4
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    • pp.585-593
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    • 2013
  • This study aims to investigate inundation characteristics such as inundated area, inundation depth according to variation in return period of design rainfall and to draw a comparison between the inundation characteristics by adapting design storm using dual-drainage model. Lidar data is used to construct terrain data with $1m{\times}1m$ resolution in Cheongju. The designed storm by return periods(10year, 30year, 50year and 200year) are acquired from Intensity Duration Frequency curve, which are distributed in 5 minutes interval using Huff's method. As a results, the inundation volume is linearly increased, but inundated area is gradually increased in accordance with swell of return period for design storm. On the other hands, as a result of calculating discharge capacity for each points, deficit of discharge capacity is not observed using designed storm of 10 year return period at every points. If the return period is increased up more than 10 years, both the deficit of discharge capacity for each PT and entire study area are enlarged drastically.

A Change of fashin IIIustration by the Ideal Type of Human Body Beauty (인체미의 이상형에 따른 패션 일러스트레이션의 변화)

  • 전경숙
    • Journal of the Korean Society of Costume
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    • v.28
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    • pp.65-84
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    • 1996
  • The purpose of this study is to analyze the relation between the beauty of human body and the fashion illustration in each period And I attained my object through the investigation of features and changes of illustration which is given a vivid description of the features and development of ideal humam body beauty. By various methods I studied this subject. Frist I refered to sundry records Secondly I investiated the fashion illustrations which are included in Vogue. On the basis of this data I grasped the ideal types of human body beauty which is founded during the social change in each 10 years. And I analyzed the relation be-tween the ideal type and fashion illustration which show the change of fashion. The summary of result is as follows. 1. In the early part of the 20th century the beauty of human body is represented with the figure of large-sized beauty which emphasize shoulder and bust. And fashion ikllustration show 9 life-size broad shoulder full bust lim waist and hourglass silhouette. 2, In the 1910s the swell of strength vanishes gradually and shoulder and sleeve are straight type. And fashion illustration show 7 life-size high waist line. And that is tublar sil-houette of high waist and streamline shape in which bust and hip are not emphasized. 3. In the 1920s the ideal type of human body beauty is straight type which shows flat bust and unexaggerate hip. And fashion illus-tration is about 8 life-size tublar silhouette of low waist and lunger and slimmer and young style in which bust and hip are not emph-asized. 4. In the 1930s the ideal is womamly slim and long style. Fashion illustration is about 8 life-size and slim & long silhouette in which waist line is emphasized and bust and hip line come out. 5. In the 1940s the ideal type is womamly style which has narrow shoulder rich bast and slim waist. And fashion illustration is about 7 life-size and hourglass silhouette which has unartificial shoulder slim waist and empha-sized bust. 6. In the 1950s the ideal type is that of ro-bust health which emphasize build and muscu-lar system. And fashion illustration is 8.5 life-size and show full bust and made waist slimmer. That is sheath silhouette. 7. In the child who has full face with large eyeball slender and long leg: narrow and immatured body comparatively big head. And fashion illus-tration is 7 life-size and show slim and long neck flat bust long and slim limbs and big head. That is H type silhouette. 8. In the 1970s the ideal type is high stat-ure flat breast small hip and wide shoulders. And fashion illustration is wide shoulders and slim waist as 11 life-size and straight sil-houete. 9. In the 1980s the ideal type is extremely emphasized breadth of shoulder because healthy body and muscle are recognized as the symbol of ideal attractiveness. And fashion il-lustration is about 8.5 life-size and show mus-cular slim type that is slim silhouette. 10 At the present time the ideal type is slim and tall type which is empasized healthy beauty. And fashion illustration is 12 life-size which has healthy body and skin So that is slim and long type.

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A Study on the Thermal Stability of Long-Term Fuel Storage and Lifetime Estimation of Rubber O-ring in Contacted with Fuel (장기 저장연료의 열안정성 및 연료접촉 고무오링의 수명예측 연구)

  • Chung, K.W.;Hong, J.S.;Kim, Y.W.;Han, J.S.;Jeong, B.H.;Kwon, T.S.;Suh, D.O.;Sung, M.J.;Kwon, Y.I.
    • Tribology and Lubricants
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    • v.34 no.5
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    • pp.197-207
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    • 2018
  • Thermal deterioration of fuel due to long-term storage influences engine performance and causes malfunctions. Fuel stability is usually evaluated via heat resistance and thermal stability during a brief heat shock at high temperature; storage stability in this scenario means that there is very little change in the quality of the fuel during long-term storage. In addition, rubber-based products such as oil seals, O-rings, and rubber hoses can influence the quality of the fuel. When these rubber products are in contact with fuel, they can swell, mechanically weaken, and occasionally crack, thus leaking low molar weight rubber and additives including plasticizer and antioxidant into the fuel to degrade its properties and shorten its useful lifetime. This study determines the thermal stabilities of three kinds of synthetic fuels by evaluating their low temperature kinematic viscosities, chemical composition changes via GC analyses, gross heat of combustion, and color changes. We evaluate the compression set of O-rings by immersing one NBR and two FKM rubber O-rings in the three synthetic fuel samples in airtight containers at variable storage temperatures for six months; from this, we estimate the lifetimes of the O-rings using the Power law model. There were very little changes in the chemical compositions and gross heat of combustion after six months of the experiment. The lifetimes are thus dependent on the materials of the rubber products, and in particular, the FKM O-ring was calculated to have a theoretical lifetime of 200 to 5,700 years. These results indicate that the synthetic fuels maintain their physical properties even after long-term storage at high temperatures, and the FKM O-ring is suitable for long-term sealing of these fuels.

A Study on Characteristics of Animal Glue depending on Pretreatment and Evaluation Condition (아교 전처리 및 평가 조건에 따른 특성연구)

  • Oh, Seong Min;Yu, Ji A;Lee, Na Ra;Kim, Tae Heon;Kim, Seong Eun;Chung, Yong Jae
    • Journal of Conservation Science
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    • v.35 no.6
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    • pp.701-708
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    • 2019
  • Animal glue is a natural adhesive made from processed skins or bones of animals. It is widely used in wooden crafts, papercrafts, dancheong painting, and pictures. Accurate evaluation of the quality of animal glues during production and use is difficult because there is no formal method for testing the glue's properties during pretreatment and measurement conditions. Thus, in this study, a series of tests were carried out by changing the conditions of swelling, temperature, and concentration of animal glue and gelatin sold on the market. Twelve types of animal glues were evaluated, having a viscosity range of 12.67 cP to 29.43 cP. The results showed that the physical characteristics of the glues were stable when allowed to swell for six h in distilled water(23℃). When 10%(by weight in distilled water) of the animal glue was measured in the reflective mode of a spectrophotometer, the optical characteristics of the glues were stable. Powdered animal glues have a medium brightness and middle-high chroma. Relative to powdered glues, stick animal glues have a low brightness and a medium chroma. Based on the results of this study, it is expected that the data can be assembled into a form so that animal glue workers can use it as a reference for the preparation of evaluation standards for testing the characteristics of animal glues.

Physicochemical Characteristics of Fe3O4 Magnetic Nanocomposites Based on Poly(N-isopropylacrylamide) for Anti-cancer Drug Delivery

  • Davaran, Soodabeh;Alimirzalu, Samira;Nejati-Koshki, Kazem;Nasrabadi, Hamid Tayefi;Akbarzadeh, Abolfazl;Khandaghi, Amir Ahmad;Abbasian, Mojtaba;Alimohammadi, Somayeh
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.1
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    • pp.49-54
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    • 2014
  • Background: Hydrogels are a class of polymers that can absorb water or biological fluids and swell to several times their dry volume, dependent on changes in the external environment. In recent years, hydrogels and hydrogel nanocomposites have found a variety of biomedical applications, including drug delivery and cancer treatment. The incorporation of nanoparticulates into a hydrogel matrix can result in unique material characteristics such as enhanced mechanical properties, swelling response, and capability of remote controlled actuation. Materials and Methods: In this work, synthesis of hydrogel nanocomposites containing magnetic nanoparticles are studied. At first, magnetic nanoparticles ($Fe_3O_4$) with an average size 10 nm were prepared. At second approach, thermo and pH-sensitive poly (N-isopropylacrylamide -co-methacrylic acid-co-vinyl pyrrolidone) (NIPAAm-MAA-VP) were prepared. Swelling behavior of co-polymer was studied in buffer solutions with different pH values (pH=5.8, pH=7.4) at $37^{\circ}C$. Magnetic iron oxide nanoparticles ($Fe_3O_4$) and doxorubicin were incorporated into copolymer and drug loading was studied. The release of drug, carried out at different pH and temperatures. Finally, chemical composition, magnetic properties and morphology of doxorubicin-loaded magnetic hydrogel nanocomposites were analyzed by FT- IR, vibrating sample magnetometry (VSM), scanning electron microscopy (SEM). Results: The results indicated that drug loading efficiency was increased by increasing the drug ratio to polymer. Doxorubicin was released more at $40^{\circ}C$ and in acidic pH compared to that $37^{\circ}C$ and basic pH. Conclusions: This study suggested that the poly (NIPAAm-MAA-VP) magnetic hydrogel nanocomposite could be an effective carrier for targeting drug delivery systems of anti-cancer drugs due to its temperature sensitive properties.

Introduction of Optimum Navigation Route Assessment System based on Weather Forecasting and Seakeeping Prediction (개상 예보 및 내항성능을 고려한 최적 항로 평가 시스템의 도입)

  • Park Gun-il;Choi Kyong-Soon;Lee Jin-Ho;Kim Mun-Sung
    • Journal of Navigation and Port Research
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    • v.28 no.10 s.96
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    • pp.833-841
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    • 2004
  • This paper treats optimal route assessment system at seaway based on weather forecasting and wave measurement through observation Since early times, captain & officer have been sailing to select the optimum route considering the weather and ship status condition empirically. However, it is rare to find digitalized onboard route support system whereas weather fax or wave and swell chart are utilized for the officer, based on officer's experience. In this paper, optimal route assessment system which is composed of voyage efficiency and safety component is introduced. Optimum route minimized ETA(estimated time of arrival) and fuel consumption is evaluated for efficient voyage considering speed loss and power increase based on wave added resistance of ship. In the view point of safety, seakeeping prediction is performed based on 3 dimensional panel method. Basically, the weather forecast is assumed to be prepared previously in order to operate this system.

Analysis of collapse course of mudstone cut slope and suggest countermeasure (이암 절토 사면의 붕괴 요인 분석 및 대책방안 제시)

  • Park, Min-Cheol
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.4
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    • pp.123-131
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    • 2018
  • This study analyzed the collapse course of a mud stone cut slope during the construction of a express and suggested a countermeasure. Experiments were carried out on bedrock mudstone to investigate the engineering characteristics and the slope stability analysis at the time the design was reviewed. In addition, stability analysis, considering the strength softening characteristics of the slope due to the Swelling-Slaking phenomenon, was also performed. As a result of the Swelling-Slaking test, the slake durability was Low-Medium, and the swell potential was Very Low. A review of the stability analysis performed at the time of the design showed different results from the actual results because LEM analysis had been performed without considering the engineering characteristics of mudstone. As a result of additional stability analysis considering the strength softening characteristics, the slope collapse point and the maximum shear strain point of the stability analysis were the same and the standard safety factor was not satisfied. As a countermeasure, a slope mitigation method was found to be most appropriate. The mitigation slope was calculated by Finite element Analysis. A comparison with BIPS to determine the applicability of a mitigation slope revealed most of the unconsolidated mudstone.

A Study on the Effect of Herbal-acupuncture with Carthami Flos at Joksamni($ST_{36}$) on Collagen-induced Arthritis in Mice (족삼리(足三里) 홍화약침(紅花藥鍼)처치가 Collagen으로 유발한 생쥐의 관절염 모델에 미치는 영향)

  • Park, Ki-Hong;Lee, Hyun
    • Journal of Acupuncture Research
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    • v.24 no.6
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    • pp.45-61
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    • 2007
  • Objectives : The purpose of this study is to observe the effects of Carthami Flos herbal-acupuncture (CF-HA) at Joksamni($ST_{36}$) on arthritis in mice induced by Collagen II. Methods : The author performed several experimental items, including arthritis evaluation, change in weight, spleen size and stenosis rate, change in cytokine level, IgG, IgM and anti-collagen II, change of immunocyte count and histological change of the CIA mouse joint. Conclusions are as follows: Results : 1. In the CF-HA, the arthritis index and rate and the incidence of arthritis were decreased as the experiment proceeded. 2. In the CF-HA, spleen swell and stenosis, joint edema and change were decreased. 3. In the CF-HA, the level of $IL-1{\beta}$, IL-6, $TNF-{\alpha}$ and $IFN-{\gamma}$ in blood serum were significantly decreased. 4. In the CF-HA, the level of IgG, IgM and anti-collagen II were decreased. 5. In the CF- HA, $IFN-{\gamma}$, $IFN-{\gamma}/IL-4$, IL-10 of the culture fluid was decreased. 6. In the CF-HA, the cell rate of $CD3e^+$ and $CD45R^+$, $CD4^+$ and $CD8^+$, $CD4^+/CD25^+$ in spleen was similar to the cell rate of the normal group. 7. In the CF-HA, the cell rate of $CD4^+/CD25^+$, $CD45R^+/CD69^+$ in a lymph node was decreased as in the normal group. 8. In the CF-HA, the cell rate of $CD3^+/CD69^+$, $CD11b^+/Gr-1^+$ in joints was decreased as in the normal group. 9. In the CF-HA, the cartilage destruction and the inflammation cell growth in the H&E stain were decreased. The collagen fiber in the M&T stain were less destructed, therefore the result was similar to the normal group. Conclusions : These results suggest that CH-HA at $ST_{36}$ has an effect in controlling immune reaction and suppressing inflammation in rheumatoid arthritis therefore, the continuous flow of the following study is expected.

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Thermal-hydraulic behaviors of a wet scrubber filtered containment venting system in 1000 MWe PWR with two venting strategies for long-term operation

  • Dong, Shichang;Zhou, Xiafeng;Yang, Jun
    • Nuclear Engineering and Technology
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    • v.52 no.7
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    • pp.1396-1408
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    • 2020
  • Filtered containment venting system (FCVS) is one of the severe accident mitigation systems designed to release containment pressurization to maintain its integrity. The thermal-hydraulic behaviors in FCVSs are important since they affect the operation characteristics of the FCVS. In this study, a representative FCVS was modeled by RELAP5/Mod3.3 code, and the Station BlackOut (SBO) was chosen as an accident scenario. The thermal-hydraulic behaviors of an FCVS during long-term operation with two venting strategies (open-and-close strategy, open-and-non-close strategy) and the sensitivity analysis of important parameters were investigated. The results show that the FCVS can operate up to 250 h with a periodic open-and-close strategy during an SBO. Under the combined effects of steam condensation and water evaporation, the solution inventory in the FCVS increases during the venting phase and decreases during the intermission phase, showing a periodic pattern. Under this condition, the appropriate initial water level is 3-4 m; however, it should be adjusted according to the environment temperature. The FCVS can accommodate a decay heat power of 150-260 kW and may need to feed water for a higher decay heat power or drain water for a lower decay heat power during the late phase. The FCVS can function within an opening pressure range from 450 kPa to 500 kPa and a closing pressure range between 250 kPa and 350 kPa. When the open-and-non-close strategy is adopted, the solution inventory increases quickly in the early venting phase due to steam condensation and then decreases gradually due to the evaporation of water; drying-up may occur in the late venting phase. Decreasing the venting pipe diameter and increasing the initial water level can mitigate the evaporation of the scrubbing solution. These results are expected to provide useful references for the design and engineering application of FCVSs.