• Title/Summary/Keyword: Mean wave period

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Physical Environment Changes in the Keum River Estuary by the Dyke Gate Operation: II. Salinity Structure and Estuary Type (하구언 수문작동으로 인한 금강 하구역의 물리적 환경변화: II. 염분구조와 하구유형)

  • Lee, Sang-Ho;Kwon, Hyo-Keun;Choi, Hyun-Yong;Yang, Jae-Sam;Choi, Jin-Yong
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.4 no.4
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    • pp.255-265
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    • 1999
  • CTD castings and current observations are taken in June, July and October, 1997 and May and July, 1998 to investigate the effect of the Keum River dyke on the structure of physical properties and the type of the Keum River estuary. Tide and tidal current relation shows that the ebbing is longer than the flooding by 1.5 hours with the early current reversing before high tide. In the rainy season (May to July), frequent large fresh water discharge during the ebbing from the dyke changes vertical salinity difference and time variation of salinity greatly near the head of the estuary, where salinity becomes lower than 2‰ in summer fresh water flooding. Halocline developed by the fresh water discharge makes two-layer structure, of which strength and depth increase in the low tide. The relationship between tide phase and surface salinity variation shows the phase lag of 2.5 hours near the head of the estuary but the standing wave relation down the estuary. This phase lag implies that a low salinity water diluted by the fresh water discharge for 2-3 hours in the ebb period moves with tidal excursion. In the dry season, vertical salinity difference reduces significantly. We calculate stratification and circulation parameters using the observed salinity structure, surface current and fresh water discharge. The Keum River estuary shows a partially mixed type, changing the stratification parameter from the rainy to the dry season. Mean flows of observed tidal current at lower and upper layer are landward and seaward, which are consistent with the circulation of a partially mixed estuary. Based upon the estuary type and circulation we suggest that the suspended materials will move toward the upstream due to low-layer mean flow and then the Keum River estuary will be a deposit environment.

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Clinical Features of Benign Infantile Convulsions with Gastroenteritis (위장관염과 동반된 양성 영아 경련의 임상적 고찰)

  • Lee, Jung Sun;Kwon, Hae Oak;Jee, Young Mee;Chae, Kyu Young
    • Clinical and Experimental Pediatrics
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    • v.48 no.7
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    • pp.753-759
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    • 2005
  • Purpose : This study was performed to characterize clinical features of benign convulsions with gastroenteritis(CwG) in infants. Methods : We reviewed clinical features of 67 episodes in 64 patients with afebrile seizure accompanied gastroenteritis admitted to Dept. of Pediatrics Bundang CHA hospital from January 2001 to June 2004. Patients with meningitis, encephalitis/encephalopathy or apparent history of epilepsy were excluded. Results : There were 32 boys and 35 girls. The age of onset ranged from 1 to 42 months($18.5{\pm}6.1$ months). The number of children admitted to the hospital with acute gastroenteritis was 2,887 in the same period. The percentage of patients with CwG was 2.3. Seizure type was exclusively generalized tonic or tonic-clonic seizure. The average number of seizures during a single episode was 3.1 (range, 1-13). Two or more seizures occurred in 53(79.1%) of the 67 episodes. Antiepileptic drugs were administered for 42 episodes. Seizure did not cease after the administration of one kind of antiepileptic drug in 23 episodes(54.7%). The seizures were rather refractory to initial antiepileptic treatment. There were no abnormalities in serum biochemistry test including glucose and electrolytes. Cerebrospinal fluid was normal in all 54 episodes. Stool cultures were negative in 49 episodes. Rotavirus was positive in stools in 51(82.3%) of 62 episodes. Norovirus was positive in stools in 2 episodes and astrovirus in 1 of 18 episodes. CT and/or MRI were performed in 15 cases and demonstrated no neuroradiologic abnormalities. Of 73 Interictal EEG, initial 24 cases showed occasional spike or sharp wave discharges from the mid-line area during stage I-II sleep, which were apparently differentiated from vertex sharp transient or K-complexes. The mean follow-up period was 5.7 months(1-36 months). Three patients experienced a recurrence of CwG, but all patients exhibited normal psychomotor development at the last follow-up. Conclusion : Afebrile infantile convulsions with gastroenteritis are brief generalized seizure in cluster with normal laboratory findings and good prognosis. Therefore CwG is likely to be categorized as situation-related seizure of special syndrome. Recognition of this entity should lead to assurance of the parents and long-term anticonvulsant therapy is not usually warranted.

Effect of Left Atrial Volume Reduction with Maze Operation on Sinus Conversion and Recovery of Left Atrial Transport Function (Maze 수술 후 동율동 및 좌심방 수축능 회복에 대한 좌심방 부피 감소 성형술의 영향)

  • Hong Seong-Beom;Ryu Sang-Wan;Jung Eun-Kyung;Jung In-Suk;Bum Min-Sun;Park Jung-Min;Lee Kyo-Sun;Kim Sang-Hyung;Ahn Byung-Hee
    • Journal of Chest Surgery
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    • v.38 no.11 s.256
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    • pp.739-745
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    • 2005
  • Background: The Maze procedure considered the most effective method of treatment for atrial fibrillation. However, the sinus conversion rates decreased due to several factors, especially enlarged left atrium. The purpose of this study was to investigate the effects of Maze procedure with aen atrial volume reduction plasty on rheumatic mitral valve disease, Material and Method: From December of 200f to July of 2004, 45 patients received mitral valve and Maze operation. The patients were placed in either group f or group 2, based on the left atrial volume reduction plasty. The presence and onset of sinus rhythm and the incidence of trans mitral A waves were monitored during the postoperative 7 days and throughout the follow up period of 3 and 6 months. Mean follow up periods were 15.8 10.1 months in group 1 and $6.1\pm2.7$ months in group 2. Result: The sinus onset were $9.88\pm12.2$ days in group 1, and $1\pm3.6$ days in group 2 (p<0.01). The sinus conversion rates in the group 1 and 2 were $65\%,\;75\%$ (p=0.07) in the postoperative 7 days, $70.5\%,\;100\%$ (p<0.01) at postoperative 3 months, and $93\%,\;100\%$ (p<0.01) at postoperative 6 months, respectively. The wave detection rates in the postoperative 7days were $31.2\%\;and\;63.6\%$, and continued to improve over time to $83.3\%\;and\;100\%$ by 6months, respectively. Conclusion: The results suggest that Maze procedure with left atrial volume reduction plasty is effective for inducing sinus rhythm and for restoring left atrial contractile function after concomitant rheumatic mitral valve surgery. However further follow up of this patients for long time is necessary.

The Effects of Pergola Wisteria floribunda's LAI on Thermal Environment (그늘시렁 Wisteria floribunda의 엽면적지수가 온열환경에 미치는 영향)

  • Ryu, Nam-Hyong;Lee, Chun-Seok
    • Journal of the Korean Institute of Landscape Architecture
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    • v.45 no.6
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    • pp.115-125
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    • 2017
  • This study was to investigate the user's thermal environments under the pergola($L\;7,200{\times}W\;4,200{\times}H\;2,700mn$) covered with Wisteria floribunda(Willd.) DC. according to the variation of leaf area index(LAI). We carried out detailed measurements with two human-biometeorological stations on a popular square Jinju, Korea($N35^{\circ}10^{\prime}59.8^{{\prime}{\prime}}$, $E\;128^{\circ}05^{\prime}32.0^{{\prime}{\prime}}$, elevation: 38m). One of the stations stood under a pergola, while the other in the sun. The measurement spots were instrumented with microclimate monitoring stations to continuously measure air temperature and relative humidity, wind speed, shortwave and longwave radiation from the six cardinal directions at the height of 0.6m so as to calculate the Universal Thermal Climate Index(UTCI) from $9^{th}$ April to $27^{th}$ September 2017. The LAI was measured using the LAI-2200C Plant Canopy Analyzer. The analysis results of 18 day's 1 minute term human-biometeorological data absorbed by a man in sitting position from 10am to 4pm showed the following. During the whole observation period, daily average air temperatures under the pergola were respectively $0.7{\sim}2.3^{\circ}C$ lower compared with those in the sun, daily average wind speed and relative humidity under the pergola were respectively 0.17~0.38m/s and 0.4~3.1% higher compared with those in the sun. There was significant relationship in LAI, Julian day number and were expressed in the equation $y=-0.0004x^2+0.1719x-11.765(R^2=0.9897)$. The average $T_{mrt}$ under the pergola were $11.9{\sim}25.4^{\circ}C$ lower and maximum ${\Delta}T_{mrt}$ under the pergola were $24.1{\sim}30.2^{\circ}C$ when compared with those in the sun. There was significant relationship in LAI, reduction ratio(%) of daily average $T_{mrt}$ compared with those in the sun and was expressed in the equation $y=0.0678{\ln}(x)+0.3036(R^2=0.9454)$. The average UTCI under the pergola were $4.1{\sim}8.3^{\circ}C$ lower and maximum ${\Delta}UTCI$ under the pergola were $7.8{\sim}10.2^{\circ}C$ when compared with those in the sun. There was significant relationship in LAI, reduction ratio(%) of daily average UTCI compared with those in the sun and were expressed in the equation $y=0.0322{\ln}(x)+0.1538(R^2=0.8946)$. The shading by the pergola covered with vines was very effective for reducing daytime UTCI absorbed by a man in sitting position at summer largely through a reduction in mean radiant temperature from sun protection, lowering thermal stress from very strong(UTCI >$38^{\circ}C$) and strong(UTCI >$32^{\circ}C$) down to strong(UTCI >$32^{\circ}C$) and moderate(UTCI >$26^{\circ}C$). Therefore the pergola covered with vines used for shading outdoor spaces is essential to mitigate heat stress and can create better human thermal comfort especially in cities during summer. But the thermal environments under the pergola covered with vines during the heat wave supposed to user "very strong heat stress(UTCI>$38^{\circ}C$)". Therefore users must restrain themselves from outdoor activities during the heat waves.