• Journal of Chest Surgery
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• v.30 no.12
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• pp.1225-1231
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• 1997

Spontaneous pneumothorax is the sudden collapse of a lung usually caused by air leakage from a subvisceral pleural blob. Responses to closed thoracostomy,thoracentesls and simple observation are usually prompt and effective. But in some cases, these are unsucceful and open thoracotomy is indicated. A clinical evaluation was performed on 242 cases(236 patients) of open thoracotomy in spontaneous pneumoth rax who were admitted and treated at department of Thoracic and Cardiovascular Surgery. Masan Samsung General Hospital during the past 9 years from January 1988 to December 1996. The results were as follows 1. The sex ratio was male predominance(M:F=11.7:1) 2. The most common age group were 2nd, 3rd decades(2nd=29.3%, 3rd=30.2%). 3. The most common chief complaints were chest pain and dyspnea(chest pain=41.7%. dryspnea= 36.8). 4. The etiologic factors of spontaneous pneumothorax were primary spontaneous pneumothorax(86.4%), tuberculosis(9.1%), COPD(3.7%) and pleuritis(0.8%). 5. The site of spontaneous pneumothorax was 52.1% in right, 45.4% in left and 2.5% in both. 6. The common indications of open thoracotomy were recurrence(44.2%), persistent air leakage(31.8%) and inadequate expansion(15.7%). 7. The operative procedures were bullectomy or mechanical pleurodesis through posterolateral thoracotomy or median sternotomy. 8. The most frequent location of bulla or blob were apical segme t oi RUL(35.1%) and apicoposterior segment of LUL(41.3 %). 9. The number of bulla or blob were mainly 1 to 5(88%), and there were no significant differences among operation indications. 10. The size of bulla or bleb were mainly below 5cm(81%)and small bulla($\leq$1cm) were predominant in recurrence group but large bulla(>5cm)were predominant in persistent air leakage and inadequate expansion group. 11. The pleural adhesion was seen in 54.5%.(Recurrence group 64.1%,Persistent air leakage group 51.9%,Inadequate expansion group 47.4%).

• Korean Journal of Veterinary Research
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• v.33 no.4
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• pp.735-746
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• 1993

Electrocardiographic parameters of amplitude and the shape of waves on the unipolar precordial chest leads in the normal Korean native cattles have been measured with a 3 channel electrocardiograph built in a computed and analysis. The study was conducted on 98 heads of mean age of 17.6 months. The wave forms of P, T and QRS complex wave in all leads showed various types. The parameters of the amplitude in the wave types showed the most frequency in each lead that were analyzed as follow : 1. In P wave, amplitudes of positive type showed a frequency of 92.9% and 93.9% in leads $CV_6LU$ and $CV_6LL$ that were $83.8{\pm}31.0{\mu}V$ and $76.0{\pm}30.7{\mu}V$, and negative type showed a frequency of 97.9% in lead V 10 that were $-80.2{\pm}29.4{\mu}V$, respectively. But the plate type in leads $CV_6RU$ and $CV_6RL$ showed frequency of 48% and 58.3%, respectively. 2. Average amplitude of the QRS complex were in a range of $277.0{\pm}154.0{\mu}V$ to $648.2{\pm}146.2{\mu}V$(mean of $418.8{\pm}139.4{\mu}V$) in all leads that were manifested the Low-Voltage QRS complex(below 1 mV in unipolar precordial leads). Average amplitudes of each wave type in the QRS complex were $-250.0{\pm}139.8{\mu}V$ and $-399.2{\pm}226.8{\mu}V$ in the QS group types that showed a frequency of 50.0% and 82.5% in the leads $CV_6LU$ and $CV_6LL$, respectively. And average amplitudes of the R group types showed a frequency of 85.6%, 56.1% and 75.8% in the $CV_6RU$, $CV_6RL$ and $V_{10}$ that were $321.5{\pm}142.1{\mu}V$, $271.6{\pm}139.9{\mu}V$ and $552.4{\pm}132.7{\mu}V$, respectively. 3. In T waves, Amplitudes of the positive type showed a frequency of 60.2%, 46.9% and 83.7% in leads of $CV_6LL$, $CV_6RU$ and $CV_6RL$ that were respectively $184.7{\pm}93.7{\mu}V$ $103.7{\pm}64.43{\mu}V$ and $111.8{\pm}39.3{\mu}V$, the negative type showed a frequency of 62.2% and 93.7% in leads $CV_6LU$ and $V_{10}$ that were $142.2{\pm}82.1{\mu}V$ and $-280.3{\pm}107.2{\mu}V$, respectively. 4. Average amplitude of ST segment were $3.7{\pm}33.1{\mu}V$, $0.9{\pm}23.1{\mu}V$, $10.9{\pm}28.6{\mu}V$, $5.8{\pm}28.3{\mu}V$ and $-34.7{\pm}48.4{\mu}V$ in leads $CV_6LL$, $CV_6RU$, $CV_6RL$, $CV_6LU$ and $V_{10}$ respectively.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.31 no.3
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• pp.101-114
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• 2019

In this study, we carry out the numerical simulation to trace the yearly shoreline change of Mang-Bang beach, which is suffering from erosion problem. We obtain the basic equation (One Line Model for shoreline) for the numerical simulation by assuming that the amount of shoreline retreat or advance is balanced by the net influx of longshore and cross-shore sediment into the unit discretized shoreline segment. In doing so, the energy flux model for the longshore sediment transport rate is also evoked. For the case of cross sediment transport, the modified Bailard's model (1981) by Cho and Kim (2019) is utilized. At each time step of the numerical simulation, we adjust a closure depth according to pertinent wave conditions based on the Hallermeier's analytical model (1978) having its roots on the Shield's parameter. Numerical results show that from 2017.4.26 to 2017.10.15 during which swells are prevailing, a shoreline advances due to the sustained supply of cross-shore sediment. It is also shown that a shoreline temporarily retreats due to the erosion by the yearly highest waves sequentially occurring from mid-October to the end of October, and is followed by gradual recovery of shoreline as high waves subdue and swells prevail. It is worth mentioning that great yearly circulation of shoreline completes when a shoreline retreats due to the erosion by the higher waves occurring from mid-March to the end of March. The great yearly circulation of shoreline mentioned above can also be found in the measured locations of shoreline on 2017.4.5, 2017.9.7, 2017.11.7, 2018.3.14. However, numerically simulated amount of shoreline retreat or advance is more significant than the physically measured one, and it should be noted that these discrepancies become more substantial for the case of RUN II where a closure depth is sustained to be as in the most morphology models like the Genesis (Hanson and Kraus, 1989).