• Title/Summary/Keyword: Tidal Effects

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Changes of Surface $M_2$ Currents as Observed by HF Radar Before and After Saemangeum Fourth Tidal Dyke Closing (새만금 4호 방조제 완성 전.후 HF 레이다로 관측된 표층 $M_2$ 조류의 변화)

  • Kim Chang-Soo;Lee Sang-Ho;Son Young-Tae;Kwon Hyo-Keun;Lee Kwang-Hee;Kim Young-Bae;Jeong Ou-Jin
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.11 no.2
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    • pp.37-48
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    • 2006
  • HF radar-derived current data obtained in 2002 and 2004 are analyzed to examine the effects of the completion of the Saemangeum 4th tidal dyke in June 2003, connecting Gogunsan-Gundo and Bieung-Do, on the coastal surface $M_2$ current pattern. Comparison between the currents by HF radar and current meter mooring showed good agreements. Counterclockwise rotation of the $M_2$ current in the observed area did not change with the dyke construction. Strong westward ebb jet from the gap of the dyke was observed in 2002 but disappeared in 2004. The complete closing of the dyke gap caused the current speed increase around the mouth of the Kem River estuary, decrease around Gogunsan-Gundo and the dyke, the changes in the direction of maximum current to north-ward from eastward and the delay of the maximum flood current occurrence around Gogunsan-Gundo and the dyke. Around Yeon-Do, the maximum flood current directed more clockwise and occurred rather earlier. These changes of the $M_2$ current ellipse characteristics imply that the effects of the dyke construction reached the area connecting Mal-Do and Yeun-Do.

Effect of Epidural Mortphine for Post-Thoracotomy Pain (개흉술후 경막외 몰핀에 의한 진통효과)

  • Yu, Ung-Cheol;Lee, Jeong-Eun;Im, Seung-Pyeong
    • Journal of Chest Surgery
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    • v.26 no.4
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    • pp.303-307
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    • 1993
  • Postoperative pain relief and the side effects of epidurally injected morphine were investigated in 10 patients who received thoracotomy. Epidural morphine injection was given via an epidural catheter after thoracotomy. The pain score[VAS] and repiratory rate were decreased and the SaO2, tidal volume and vital capacity were increased significantly after epidural morphine injection. The analgesia of epidural morphine lasted for 13 hours with average. The side effects of epidural morphine were few and mild, but urinary retention was in 10%[1/10] of total patients.

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A Study on the Design of High-Frequency Jet Ventilator Using PLL system (위상동기루프 방식을 이용한 고빈도 JET환기장치의 설계에 관한 연구)

  • Lee, Joon-Ha;Chung, Jae-Chun
    • Journal of Yeungnam Medical Science
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    • v.6 no.2
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    • pp.63-70
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    • 1989
  • This paper describes to design and to examine the mechanical characteristics of high frequency jet ventilator. The device consists of Phase lock loop(PLL) system, solenoid valve driving control part and Air regulating system. This study is carried out by changing several factors such as endotracheal tube(E.T. tube)diameter, injector cannula diameter, 1%, and frequency(breaths/mim.) having direct effects on the gas exchange as well as parameters of the entrained gas by venturi effects, so as to measure the tidal volume and minute volume. This system characteristics were as follows : 1) Frequency : 6-594bpm 2) Inspiration time : 1-99% 3) Variance of input air pressure : 1-30PSI.

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Phase Space as a Tool for Understanding Galaxy Cluster Environmental Effects

  • Smith, Rory;Rhee, Jin Su;Choi, Hoseung;Yi, Sukyoung
    • The Bulletin of The Korean Astronomical Society
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    • v.41 no.1
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    • pp.34.3-35
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    • 2016
  • A galaxy-cluster phase space diagram is a simple plot of clustocentric velocity versus clustocentric radius for each member of the cluster. Using state-of-the-art, cosmological hydrodynamical simulations, we investigate where simulated galaxies fall in phase space. We find the galaxies with different cluster infall times often separate cleanly in phase space. We also investigate how a galaxy's location in phase space is correlated with its tidal mass loss, and ram pressure stripping. By comparing our simulated cluster galaxies to observed cluster galaxies, we show how phase space diagrams are essential tools for understanding environmental effects acting on cluster galaxies.

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Tackling Proximity Effects in Nonmarket Valuation Approaches : An Example of Contingent Valuation Method (비시장재화의 가치평가에 있어서 근접효과(Proximity Effects)의 검증에 관한 연구 : 조건부가치평가법을 중심으로)

  • Jeon, Chul-Hyun;Shin, Hio-Jung;Joo, Hye-Jin
    • Environmental and Resource Economics Review
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    • v.19 no.1
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    • pp.101-127
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    • 2010
  • The purpose of the research is to tackle proximity effects (PEs) when nonmarket valuation method CVM is applied to environmental goods such as tidal flats. 1,000 households are surveyed in the ratio of national household for the research. The sample are reclassified into five areas by 30-minute distance. Log-linear are used to analysis PEs in the research. On conclusion log-linear model regarding income effects proves that PEs are apparently represented in NMVMs(${\theta}_1$ >0. ${\theta}_2$ >0 and $dum1{\neq}0$, $dum2{\neq}0$, $dum3{\neq}0$, $dum4{\neq}0$) as a result of a 5 per cent significant level of t -test and F-test, finally rejecting the null hypothesis. In addition, WTP of area I respondents shows 26 per cent more then that of area V respondents, which is from \87,969 to \64,866 in the open-ended format. Finally, the research proves that the PEs in CVM are evidently represented with the econometric model, hence the PEs have to be embedded into the questionnaire of non-market valuation methods with the environmental goods to reduce the underestimation and improve the estimation accuracy.

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Histamine Bronchial Provocation Test -Timed Tidal Breathing Technique- (히스타민 기관지유발 검사 -일정시간 흡입법-)

  • Chung, Yeon-Tae;Won, Kyung-Sook;Park, Hae-Shim
    • Tuberculosis and Respiratory Diseases
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    • v.41 no.3
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    • pp.270-276
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    • 1994
  • Background: The measurement of nonspecific bronchial hyperreactivity is valuable for diagnosis and management of bronchial asthma. Methacholine or histamine is used for the pharmacologic provocation test. Usually a methacholine bronchial provocation test is performed by a dosing technique with counted number of breaths. A dosimeter is indispensable in the dosing technique. Recently a timed tidal breathing technique which dose not need an expensive dosimeter was introduced. We measured the degree of nonspecific bronchial hyperreactivity to histamine using a simple timed tidal breathing technique. Method: Forty two healthy volunteers, 12 patients with bronchial asthma(BA), 10 patients with rhinitis(RH) and 10 patients with upper respiratory infection(URI) participated in the study. The subject's nose was clipped and inhalation continued during tidal breathing for 2 minutes via a face mask. $FEV_1$ was measured at 30 seconds, 90 seconds after inhalation and inhalation of next solution was continued until there was a fall in $FEV_1$ of 20%. Histamine PC20 was defined as the concentration at 20% fall of $FEV_1$ and it was obtained from the log dose-response curve by linear interpolation. Results: Inhalation of serial dilution of histamine could be performed in all patients without significant side effects. The geometric mean${\pm}$standard deviation of histamine PC20 in healthy volunteers is $8.27{\pm}2.22mg/ml$, BA group $0.33{\pm}3.02mg/ml$, RH group $0.85{\pm}3.24mg/ml$, and URI group $1.47{\pm}1.98mg/ml$. Conclusion: Histamine bronchial provocation test using timed tidal breath method is a simple and suitable tool for management of patients with bronchial hyperreactivity.

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Analysis of Tidal Effects on Network-based GPS Positioning (조석영향에 의한 망기반 GPS 측위 변화 분석)

  • Yoon, Ha-Su;Hong, Chang-Ki;Kwon, Jay-Hyoun;Choi, Yun-Soo
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2010.04a
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    • pp.31-34
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    • 2010
  • The rover positioning is performed by estimating the baseline vector components in doubledifference positioning mode. This means that relative displacement due to the tide effects can be neglected when the distance between the reference and rover station is relatively short. However, the tide effects should be carefully modeled and removed as the baseline length gets longer. In this study, the relative displacement over the Korean Peninsula due to tide effects are examined through the numerical analysis. The results show that the tide modeling is required for the precise GPS positioning at cm-level accuracy.

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Local Environmental Effects on AGN Activities

  • Kim, Jaemin;Yi, Sukyoung K.
    • The Bulletin of The Korean Astronomical Society
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    • v.38 no.2
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    • pp.44.2-44.2
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    • 2013
  • The local environmental effects on the active galactic nucleus(AGN) activity has been studied by many authors, but there is still controversy. We performed statistical analysis for nearby(0.01 < z < 0.05) volume limited(Mr < -19) sample via visual inspection based on Sloan Digital Sky Survey Data Release7. We visually inspect around 50,000 galaxy images to find peculiar objects which show not only ongoing merging features and tidal features, but also post merging features like shell or ring structures. We found that the frequency of AGN host galaxies is at least 2 times higher among peculiar galaxies than non-peculiar galaxies, and this trend is still visible when galaxy properties such as color or stellar mass are fixed. Furthermore, L[OIII] of peculiar galaxies is found to be more increased than those of normal galaxies. The majority of the most luminous AGN hosts show peculiar feature, which indicates that the luminous AGN galaxies may be the result of the local environmental effects. In addition, the enhancement of L[OIII] in peculiar galaxies is more significant for bluer galaxies, which implies that AGN activity is enhanced effectively when gas is available. In order to ensure our results, we also checked it for a smaller subsample with 2 magnitude deeper monochromatic images provided by SDSS Stripe82 database, and found consistent results. Overall, the results of this study tell us that the local environment of galaxies affects the frequency as well as the strength of AGN activity.

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Inhibitory effects of 2,6-di-tert-butyl-4-hydroxymethylphenol on asthmatic responses to ovalbumin challenge in conscious guinea pigs

  • Jeong, Seul-Yong;Lee, Ji-Yun
    • The Korean Journal of Physiology and Pharmacology
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    • v.22 no.1
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    • pp.81-89
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    • 2018
  • This study evaluated the anti-asthmatic activities of 2,6-di-tert-butyl-4-hydroxymethylphenol (DBHP) that is a potent phenolic antioxidant in edible vegetable oil. The effects of DBHP on bronchial asthma were evaluated by determining the specific airway resistance (sRaw) and tidal volume (TV) during the immediate asthmatic response (IAR) and the late-phase asthmatic response (LAR) in guinea pigs with aerosolized ovalbumin-induced asthma. Recruitment of leukocytes and the levels of biochemical inflammatory mediators were determined in the bronchoalveolar lavage fluids (BALFs), and histopathological surveys performed in lung tissues. DBHP significantly inhibited the increased sRaw and improved the decreased TV on IAR and LAR, and also inhibited recruitment of eosinophils and neutrophils into the lung, and release of biochemical inflammatory mediators such as histamine and phospholipase $A_2$ from these infiltrated leukocytes, and improved pathological changes. However, anti-asthmatic activities of DBHP at oral doses of 12.5 to 50 mg/kg was less than those of dexamethasone (5 mg/kg, p.o.) and cromoglycate (10 mg/kg, p.o.), but more potent or similar to that of salbutamol (5 mg/kg, p.o.). These results in the present study suggest that anti-asthmatic effects of DBHP in the guinea pigs model of OVA-induced asthmatic responses principally are mediated by inhibiting the recruitments of the leukocytes and the release of biochemical inflammatory mediators from these infiltrated leukocytes.

Deposition Characteristics of the Sandbar and Estimation of the Mass Transport Flux in the Nakdong Estuary (낙동강 하구역의 사주 퇴적특성과 물질수송플럭스 산정)

  • YOON RAN-SAM;LEE IN-CHEOL;Ryu CHEONG-RO
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2004.05a
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    • pp.131-137
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    • 2004
  • This paper is intended as an investigation of the deposition characteristics and mass transport flux estimation in the Nakdong estuary. In order to understand the effects of the tidal current circulation which influenced to an estuary terrain change, the seawater circulation calculation by the use of 2D numerical model for the three cases of without riverflow, mean and flood riverflow quantity condition practiced and each sectional net-flux of water quantity between sandbars(so called, dung) estimated. It may be that an estuary terrain change due to the large scale construction and reclamation at the Nakdong estuary influence to the long-time deposition characteristics. by the revim for the old research, we know that the development of the local sandbars has been moved toward the east-side from the west-side estuary area after the construction of the Nakdong river dike, at present the strong-acted location is the Bakhap-dung of the front sea of Tadea. The seawater circulation pattern at this large scale area of tidal flat bring on a change due to the water quantity outflowing from the Nakdong river. Base on the calculated results for the section net-flux of water quantity, we see that the accumulating action very strong at the local sea around Jangjado, Bakhapdung and Tadae for the case of flood riverflow quantity condition, but at the local sea around Jinudo for the another cases. Consequently, it is emphasized that in the Nakdong estuary the main sensitive regions which influenced from the discharge of riverflow were the local sea around Jangjado, Bakhapdung, Tadae and Jinudo.

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