• Title/Summary/Keyword: SWAN

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Assessment of surface current from coastal ocean model in the Youngil Bay (연안해양모델을 통한 영일만의 표층해류 평가)

  • Kim, Dong Hyeon;Hwang, Jin Hwan
    • Proceedings of the Korea Water Resources Association Conference
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    • 2022.05a
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    • pp.231-231
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    • 2022
  • 하구에서의 흐름은 하천의 담수와 바다에서부터 유입되는 염수, 조석, 파랑 등으로 인해 복잡한 흐름구조와 혼합 양상을 보인다. 특히 만 내에 하천이 있을 경우 만의 해류특성은 하구에서의 혼합과 이송에 지배적인 영향을 미치며, 하천에서부터 방류되는 입자들은 만의 해류특성 따라 만에서의 체류시간과 이송이 결정된다. 잔차류 특성에 의한 순 물질 플럭스의 방향과 조석비대칭에 따른 하구에서의 퇴적 형태들이 결정되며, 이로 인해 하구에서의 퇴적물 퇴적 및 물질의 집적 위치, 하구 인근과 만에서의 환경변화에 영향을 줄 수 있다. 따라서 만 내에서의 혼합과 입자의 이송확산, 하천 담수의 영향역 등과 같은 만과 하천의 흐름 특성을 이해하는 것은 연안 및 하구의 환경 및 관리에 중요하다. 본 연구에서는 영일만과 형산강을 대상으로 계절변화에 따른 영일만 내 흐름과 형산강 하구에서의 퇴적양상에 대해 수치모의를 통해 수행하였다. 수치모델로는 천수방정식으로 준 3차원 유동해석을 하는 Delft-3D Flow와 파랑모형인 SWAN 모델을 결합하여 형산강하구와 영일만의 유동을 해석하였다. 상류개방경계는 형산강하구 9 km, 하류개방경계는 영일만 외해 50 km로 설정하였고, 경계조건은 대상지역의 관측소 자료와 전지구 모형자료를 결합하여 구성하였다. 또한, 라그랑쥬 입자추적모델을 통해 형산강 상류에서 유입한 입자들의 영일만 내 체류시간과 집적 위치를 평가하였다.

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Macrotidal Beach Classifications Considering Beach Profiles and Changes: The Case of Beaches in Taean Region (2017-2018) (지형형태와 변화를 반영한 대조차 해빈 분류: 태안지역 해빈을 사례로(2017-2018))

  • Kim, Chan Woong
    • Journal of The Geomorphological Association of Korea
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    • v.26 no.4
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    • pp.47-65
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    • 2019
  • A case study was conducted in Taean region to seek a more detailed macrotidal beach classification than existing beach classification models (Masselink and Short, 1993). Seepage and ridge & runnel were used for classification. On 20 beaches, 68 transects were surveyed 5 times using VRS-GPS. Cross-section area from the transect profiles, mean grain size from sediment analysis, significant wave height from Swan-wave modeling and beach embaymentization from aerial photograph analysis were used to identify the characteristics of the individual types. The transects were classified into 5 types in Taean region; Type 1: low tidal terrace, Type 2: low tidal terrace & ridge, Type 3: dissipative, Type 4: seasonal ridge, and Type 5: ridge & runnel. Generally, seepage was related to coarse sediment size and ridge & runnel was related to high significant wave height. Each type has different characteristics and there was a tendency between the types. The low tidal terrace type had coarse sediments, because this type is excluded from the littoral cell. In this study, the ridge and runnel type could be applied to the classification because the study area is limited only to the macrotidal environment in Taean region.

Volatility analysis and Prediction Based on ARMA-GARCH-typeModels: Evidence from the Chinese Gold Futures Market (ARMA-GARCH 모형에 의한 중국 금 선물 시장 가격 변동에 대한 분석 및 예측)

  • Meng-Hua Li;Sok-Tae Kim
    • Korea Trade Review
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    • v.47 no.3
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    • pp.211-232
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    • 2022
  • Due to the impact of the public health event COVID-19 epidemic, the Chinese futures market showed "Black Swan". This has brought the unpredictable into the economic environment with many commodities falling by the daily limit, while gold performed well and closed in the sunshine(Yan-Li and Rui Qian-Wang, 2020). Volatility is integral part of financial market. As an emerging market and a special precious metal, it is important to forecast return of gold futures price. This study selected data of the SHFE gold futures returns and conducted an empirical analysis based on the generalised autoregressive conditional heteroskedasticity (GARCH)-type model. Comparing the statistics of AIC, SC and H-QC, ARMA (12,9) model was selected as the best model. But serial correlation in the squared returns suggests conditional heteroskedasticity. Next part we established the autoregressive moving average ARMA-GARCH-type model to analysis whether Volatility Clustering and the leverage effect exist in the Chinese gold futures market. we consider three different distributions of innovation to explain fat-tailed features of financial returns. Additionally, the error degree and prediction results of different models were evaluated in terms of mean squared error (MSE), mean absolute error (MAE), Theil inequality coefficient(TIC) and root mean-squared error (RMSE). The results show that the ARMA(12,9)-TGARCH(2,2) model under Student's t-distribution outperforms other models when predicting the Chinese gold futures return series.

Flâneur in Balzac and Baudelaire (발작과 보들레르의 배회자)

  • Hyub Lee
    • The Journal of the Convergence on Culture Technology
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    • v.9 no.6
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    • pp.737-742
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    • 2023
  • This paper attempts to analyze how Paris was transformed by Haussman through comparing flaneurs in works by Balzac and Baudelaire. In both writers' works, flâneurs as the emblems of modernity observe Paris, especially architecture. Although representative of modernity, they are ambivalently obsessed with the heritage of the past. Balzac's The Wrong Side of Paris, Godefroid as a male bourgeois, is a flaneur observing antiquated architectures, the heritage of past. In Baudelaire's "The Swan for Victor Hugo" the flaneur passing through the modern Caroussel feels the Old Paris is gone. In "Parisian Dream," illusionary Paris exhibits metopolitan imagery wrought by capitalism led by Napoleon the third. The difference between the two writers demonstrate how Paris was changed by modernity.

A Study on Goddesses Hair Arts Shown in History of Arts (미술사에 표현된 여신의 헤어 아트 연구)

  • Lee, Hyun-Jin;Kim, Sun-Ah
    • Fashion & Textile Research Journal
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    • v.9 no.6
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    • pp.663-670
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    • 2007
  • Arts is the expression of reasoning and conscious life of human and arouse human the concept of existence, utmost emotion and excellent thoughts. Also it makes humans life very abundant. I make it come first to get rid of the art thirst on the opposite sight of technical one for hair as on part of humans body. Next purpose is that to confirm the esthetic value of 'hair arts' by solidify the academic ground of beauty arts through creating 'hair arts' works and learning and make the direction for the beauty industry and education of the next generation. In this study I investigated the Greek myth and the hair styles of ancient Greek Goddesses. On the basis of that symbols I elaborated hair formative works made of metal and studied, analyzed and displayed that. Work No.1 'aphne' pictures the second of changing into a laurel tree avoiding the love. Secondly 'Muse Erato' was exhibited the peaceful figure that have enough the fine melodies. 'Leda' brings out the feature of Leda resembling a swan and the fourth piece, 'Eos' conveys the brilliant and mystery of dawn. So this study conducted based on the concept of practical hair and have made efforts to be close to theoretical manufacturing research needed at making hair arts works and academic one needed at organic design composition for pioneering new field, 'art hair.' I hope these 'hair arts' works make creativity of the practise hair alive. It will be very thankful to me if this study can help even though slightly for splendid beauty arts to make its status firm as a one part of arts, and there are following studies.

A Study on the Pulmonary Hemodynamic Changes before and after PEEP in ARDS (호흡부전증에세 호기말 양압호흡법 치료 전후의 폐혈류역학적 변화에 관한 연구)

  • Chung, June-Key;Shin, Seong-Hae;Khang, Shin-Kwang;Park, Sung-Ki;Lee, Myung-Chul;Cho, Bo-Youn;Koh, Chang-Soon;Kim, Yong-Lack;Kim, Kwang-Woo
    • The Korean Journal of Nuclear Medicine
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    • v.18 no.1
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    • pp.45-53
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    • 1984
  • The purpose of this study is to observe the changes of pulmonary capillary permeability and various hemodynamic parameters before and after Positive End-Expiratory Pressure(PEEP) in Adult Respiratory Distress Syndrome (ARDS). Using a canine oleic acid induced ARDS model, we measured the pulmonary capillary permeability with a slope of lung: heart radioactivity ratio, hemodynamic parameters with Swan-Ganz catheter and blood gas tensions. 1) In normal and ARDS dogs, the PEEP didn't significantly influence the slope of lung: heart radioactivity ratio. But in ARDS group the slope index was increased compaired with that of control group (p<0.05). 2) Also in ARDS group, $PaO_2$ was significantly decreased, and $PaCO_2,\;PvCO_2$, MPAP, $AaDO_2$, Qs/Qt were significantly increased compared with those of control group (p<0.05). 3) In normal dogs, the PEEP didn't influence blood pH or gas tension, $AaDO_2$, Qs/Qt, or hemodynamics. 4) In ARDS dogs, however, the PEEP significantly increased $PaO_2$ and decreased $AaDO_2$, Qs/Qt (p<0.05).

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Review of Acute Traumatic Closed Mallet Finger Injuries in Adults

  • Botero, Santiago Salazar;Diaz, Juan Jose Hidalgo;Benaida, Anissa;Collon, Sylvie;Facca, Sybille;Liverneaux, Philippe Andre
    • Archives of Plastic Surgery
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    • v.43 no.2
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    • pp.134-144
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    • 2016
  • In adults, mallet finger is a traumatic zone I lesion of the extensor tendon with either tendon rupture or bony avulsion at the base of the distal phalanx. High-energy mechanisms of injury generally occur in young men, whereas lower energy mechanisms are observed in elderly women. The mechanism of injury is an axial load applied to a straight digit tip, which is then followed by passive extreme distal interphalangeal joint (DIPJ) hyperextension or hyperflexion. Mallet finger is diagnosed clinically, but an X-ray should always be performed. Tubiana's classification takes into account the size of the bony articular fragment and DIPJ subluxation. We propose to stage subluxated fractures as stage III if the subluxation is reducible with a splint and as stage IV if not. Left untreated, mallet finger becomes chronic and leads to a swan-neck deformity and DIPJ osteoarthritis. The goal of treatment is to restore active DIPJ extension. The results of a six- to eight-week conservative course of treatment with a DIPJ splint in slight hyperextension for tendon lesions or straight for bony avulsions depends on patient compliance. Surgical treatments vary in terms of the approach, the reduction technique, and the means of fixation. The risks involved are stiffness, septic arthritis, and osteoarthritis. Given the lack of consensus regarding indications for treatment, we propose to treat all cases of mallet finger with a dorsal glued splint except for stage IV mallet finger, which we treat with extra-articular pinning.

A Case Report of Primary Pericardial Malignant Epitheloid Mesothelioma (원발성 심막 악성 중배엽 상피종 1예)

  • Chung, Moon-Ho;Hyun, Myong-Su;Kim, Yeung-Cho;Shim, Bong-Sup;Kim, Chong-Sul;Lee, Dong-Hub;Lee, Chul-Ju;Kang, Myun-Sik
    • Journal of Yeungnam Medical Science
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    • v.3 no.1
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    • pp.301-306
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    • 1986
  • Primary pericardial mesothelioma is a rare tumor of mesodermal origin that is infrequently diagnosed antemortem and survival is short. A 60 year old male case of pericardial mesothelioma(epitheloid type) is reported. He was admitted to Yeungnam University Hospital because of chest pain, dyspnea, orthopnea and nonproductive cough. Chest x-ray suggested pericardial effusion, 2-D echocardiography showed echo free spaces of massive pericardial effusion and areas of thick hyperrefractile echoes arising from the pericardium. Pericardiocentesis was attempted and aspirated fluid was bloody exudate. Pericardial window operation with biopsy was done. Swan-Ganz catheterization showed equalization between right atrial pressure and pulmonary capillary wedge pressure. The pathologic diagnosis was established by histologic finding at pericardial biopsy.

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Experimental Study of Shape and Pressure Characteristics of Solitary Wave generated by Sluice Gate for Various Conditions (Sluice Gate를 이용한 고립파 발생조건에 따른 형상 및 압력 특성에 관한 실험적 연구)

  • Cho, Jae Nam;Kim, Dong Hyun;Lee, Seung Oh
    • Journal of the Korean Society of Safety
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    • v.31 no.2
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    • pp.70-75
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    • 2016
  • Recently, coastal erosion has been widely in progress and the erosion level becomes also serious in the world wide, espeically in East Sea in Korea. Since it would threaten the life, economics and security risk, it is necessary to much comprehend the reason why coastal erosion has occurred according to the geographical characteristics. Meanwhile, analysis about hydrodynamics of the solitary wave such as tunami in swash zone is needed for the best management practice of coastal erosion. Solitary wave is nonlinear wave and can be reproduced in the laboratoy scale by openning suddenly a sluice gate with water head difference, of which methodology was found in the literature, since it could be simply determined by a significant wave height. Thus, in this sutdy the generation of solitary wave was experimentalized using the sluice gate. Experimental conditions were classified by angles of a beach slope, a water level in a beach slope and a difference of water level between in a headtank and a channel bed. Two kinds of dimensionless analyses based from experimental results in this study were presented; the first analysis indicates nondimensionalization between the wave height and the water level in a beach slope in order to investigate characteristics of solitary wave approaching the beach. The second shows the other nondimensionalization between dynamic pressure and static pressure on a beach slope to investigate the relationship between wave breaking and wave pressure. Under the same conditions as laboratory experiments, the numerical results computed with a SWAN model embedded in FLOW 3D were compared in terms of wave height, and pressure on the beach slope, which shows good agreement with each other. Overall results from this study could provide fundamental hydraulic data for the reliabile verification of numerical simulation results about coastal erosion in swash zone caused by solitary waves.

Calculating Expected Damage of Breakwater Using Artificial Neural Network for Wave Height Calculation (파고계산 인공신경망을 이용한 방파제 기대피해도 산정)

  • Kim, Dong-Hyawn;Kim, Young-Jin;Hur, Dong-Soo;Jeon, Ho-Sung;Lee, Chang-Hoon
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.22 no.2
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    • pp.126-132
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    • 2010
  • An approach to calculating expected damage of breakwater assisted by artificial neural network was developed. Wave height in front of a breakwater was predicted by a trained artificial neural network with inputs of wave height in deep ocean and tidal level. Prediction results by the neural network can be comparable to that by professional numerical model for wave transformation. Using the wave prediction neural network, it was very easy and fast to obtain a number of significant waves at breakwater and finally analysis time for expected damage can be shortened. In addition, the effect of considering tidal level in the calculation of expected damage was revealed by comparing the expected damages with and without tidal variation. Therefore, it was pointed out that tidal variation should be considered to improve prediction accuracy.