• 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.

• Tuberculosis and Respiratory Diseases
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• v.50 no.3
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• pp.343-352
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• 2001

Background : Advanced chronic obstructive pulmonary disease is characterized by progressive pulmonary hypertension leading to right heart dysfunction, which plays a Important role in clinical evaluation but remains difficult and challenging to quantify. The noninvasive doppler echocardiographic value referred to as the Tei index has been suggested as a simple, reproducible and reliable parameter of the right ventricular function. The purpose of this was to assess the right ventricular function in patients with chronic obstructive pulmonary disease using the Tei index and to evaluate its relationship with the pulmonary functional status. Methods : The study population comprised of 26 patients with chronic obstructive pulmonary disease and 10 normal control subjects. The Tei index was obtained by dividing the sum of the isovolumetric contraction and the relaxation times by the ejection time using a pulsed-wave doppler. It was compared with the other available Doppler echocardiographic parameters of systolic or diastolic function and with the pulmonary function of the patients. Results : The Tei indices of the patients with COPD were significantly higher than those of normal subjects($0.45{\pm}0.17$ vs. $0.27{\pm}0.03$, p<0.01). The isovolumetric contraction time/ejection time($0.32{\pm}0.08$ vs. $0.25{\pm}0.05$, p<0.05), the isovolumetric relaxation time/ejection time($0.29{\pm}0.16$ vs. $0.15{\pm}0.08$, p<0.05)and the preejection period/ejection time ($0.46{\pm}0.10$ vs. $0.38{\pm}0.06$, p<0.05) were prolonged and the ejection time ($255.2{\pm}32.6$ vs. $314.2{\pm}16.5$ msec, p<0.05) was significantly shortened in patients with COPD compared to normal subjects. The tei indices were inversely correlated with the $FEV_1$ (r=-0.46, p<0.05) and were prolonged significantly in patients with a severe obstructive ventilatory dysfunction(less than 35% of predicted $FEV_1$) compared to those with a mild and moderate ventilatory dysfunction. The tei indices showed an inverse correlation to with the ejection time (r=-0.469), the isovolumetric contraction time/ejection time(r=0.453), the isovolumetric relaxation time/ejection time(r=0.896) and the preejection period/ejection time(r=0.480). Conclusion : The tei index appeared to be a useful noninvasive means of evaluating the right ventricular function. It revealed a significant correlation with the pulmonary function in patients with COPD.

• Atmosphere
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• v.23 no.3
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• pp.293-305
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• 2013

Nonhydrostatic effects on convectively forced mesoscale flows in two dimensions are numerically investigated using a nondimensional model. An elevated heating that represents convective heating due to deep cumulus convection is specified in a uniform basic flow with constant stability, and numerical experiments are performed with different values of the nonlinearity factor and nonhydrostaticity factor. The simulation result in a linear system is first compared to the analytic solution. The simulated vertical velocity field is very similar to the analytic one, confirming the high accuracy of nondimensional model's solutions. When the nonhydrostaticity factor is small, alternating regions of upward and downward motion above the heating top appear. On the other hand, when the nonhydrostaticity factor is relatively large, alternating updraft and downdraft cells appear downwind of the main updraft region. These features according to the nonhydrostaticity factor appear in both linear and nonlinear flow systems. The location of the maximum vertical velocity in the main updraft region differs depending on the degrees of nonlinearity and nonhydrostaticity. Using the Taylor-Goldstein equation in a linear, steady-state, invscid system, it is analyzed that evanescent waves exist for a given nonhydrostaticity factor. The critical wavelength of an evanescent wave is given by ${\lambda}_c=2{\pi}{\beta}$, where ${\beta}$ is the nonhydrostaticity factor. Waves whose wavelengths are smaller than the critical wavelength become evanescent. The alternating updraft and downdraft cells are formed by the superposition of evanescent waves and horizontally propagating parts of propagating waves. Simulation results show that the horizontal length of the updraft and downdraft cells is the half of the critical wavelength (${\pi}{\beta}$) in a linear flow system and larger than ${\pi}{\beta}$ in a weakly nonlinear flow system.

• Journal of Navigation and Port Research
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• v.26 no.1
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• pp.106-111
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• 2002

The estimation of pile bearing capacity is important since the design details are determined from the result. There are numerous ways of determining the pile design load, but only few of them are chosen in the actual design. According to the recent investigation in Korea, the formulas proposed by Meyerhof based on the SPT N values are most frequently chosen in the design stage. In the study, various static and dynamic formulas have been used in predicting the allowable bearing capacity of a pile. Further, the reliability of these formulas has been verified by comparing the perdicted values with the static and dynamic load test measurements. Also, in most cases, these methods of pile bearing capacity determination do not take the time effect consideration, the actual allowable load as determined from pile load test indicates severe deviation from the design value. The principle results of this study are summarized as follows : As a result of estimate the reliability in criterion of the Davisson method, t was showed that Terzaghi & Peck >Chin>Meyerhof > Modified Meyerhof method was the most reliable method for the prediction of bearing capacity. Comparisons of the various pile-driving formulas showed that Modified Engineering News was the most reliable method. However, a significant error happened between dynamic bearing capacity equation was judged that uncertainty of hammer efficiency, characteristics of variable, time effect etc... was not considered. As a result of considering time effect increased skin friction capacity higher than end bearing capacity. It was found out that it would be possible to increase the skin friction capacity 1.99 times higher than a driving. As a result of considering 7 day's time effect, it was obtained that Engineering news, Modified Engineering News, Hiley, Danish, Gates, CAPWAP(CAse Pile Wave Analysis Program) analysis for relation, repectively, $Q_{u(Restrike)} / Q_{u(EOID)} = 0.98t_{0.1}$ , $0.98t_{0.1}$, $1.17t_{0.1}$, $0.88t_{0.1}$, $0.89t_{0.1}$, $0.97t_{0.1}$.

• Progress in Medical Physics
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• v.10 no.1
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• pp.33-40
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• 1999

Purpose: To simulate and measure the signal intensity of various tissues near bone interface in 2D and 3D neurological MR images. Materials and Methods: In neurological proton density (PD) weighted images, every component in the head including cerebrospinal fluid (CSF), muscle and scalp, with the exception of bone, are visualised. It is possible to acquire images in 2D or 3D. A 2D fast spin-echo (FSE) sequence is chosen for the 2D acquisition and a 3D gradient-echo (GE) sequence is chosen for the 3D acquisition. To find out the signal intensities of CSF, muscle and fat (or scalp) for the 2D spin-echo(SE) and 3D gradient-echo (GE) imaging sequences, the theoretical signal intensities for 2D SE and 3D GE were calculated. For the 2D fast spin-echo (FSE) sequence, to produce the PD weighted image, long TR (4000 ms) and short TE$_{eff}$ (22 ms) were employed. For the 3D GE sequence, low flip angle (8$^{\circ}$) with short TR (35 ms) and short TE (3 ms) was used to produce the PD weighted contrast. Results: The 2D FSE sequence has CSF, muscle and scalp with superior image contrast and SNR of 39 - 57 while the 3D GE sequence has CSF, muscle and scalp with broadly similar image contrast and SNR of 26 - 33. SNR in the FSE image were better than those in the GE image and the skull edges appeared very clearly in the FSE image due to the edge enhancement effect in the FSE sequence. Furthermore, the contrast between CSF, muscle and scalp in the 2D FSE image was significantly better than in the 3D GE image, due to the strong signal intensities (or SNR) from CSF, muscle and scalp and enhanced edges of CSF. Conclusion: The signal intensity of various tissues near bone interface in neurological MR images has been simulated and measured. Both the simulation and imaging of the 2D SE and 3D GE sequences have CSF, fat and muscle with broadly similar image intensity and SNR's and have succeeded in getting all tissues about the same signal. However, in the 2D FSE sequence, image contrast between CSF, muscle and scalp was good and SNR was relatively high, imaging time was relatively short.

• Korean Journal of Heritage: History & Science
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• v.53 no.3
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• pp.202-223
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• 2020

This purpose of this article is to identify the original form of the gilt-bronze ornamental pieces unearthed from the east part of the third wooden coffin in the Naju Bogam-ri Jeongchon (NBJ) tombs. The gilt-bronze ornamental pieces were all small, measuring less than 3cm in size and about 0.2cm in thickness, and only 19 or more small pieces were identified. In each piece of gilt decoration, a circular perforation, convex pattern, leaf-shaped spangle (瓔珞), 2 small holes for attaching spangles and gilt-bronze thread, 2 small holes for unknown purposes, and a continuous dot pattern of about 0.05 cm can be observed. As a result, it was judged that the gilt-bronze pieces excavated from the NBJ No. 1 chamber were part of the Headband Crown. Therefore, type 1 and type 3 of the gilt-bronze pieces were determined to be part of the Headband, and type 2 to be part of the Vertical Ornaments. Based on previous results, two types of restoration were proposed for NBJ No. 1 tomb gilt-bronze ornaments. In the first restoration proposal, there are wave-shaped dot patterns on the top and bottom of the crown, and the middle decoration is a spangle, circular perforation and spangle and a convex-pattern. In the second restoration plan, one row of convex patterns was added among the decorations in the middle of the first. The same type of vertical ornament was found in the Sochang (小倉) collection crown, but the overall structure and shape of the crown were completely different. On the other hand, the use of small holes of unknown use, as seen in the crown, was presumed to represent holes for fixing to a cap of organic matter. The restored NBJ No. 1 tomb gilt-bronze crown is characterized by circular punching, which makes it difficult to find an analogy in the other Three Kingdoms-period crowns. Unlike the existing halls in Gaya, Mahan, and Baekje, each district has a unique shape and decoration. The gilt-bronze crown excavated from NBJ No. 1 tomb is thought to reflect these characteristics.

• Clinical and Experimental Pediatrics
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• v.45 no.12
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• pp.1528-1533
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• 2002

Purpose : Isolated noncompaction of the ventricular myocardium(INVM) is one of the unclassified cardiomyopathies that is characterized by numerous, excessively prominent trabeculations, and deep intertrabecular recesses. We performed this study to evaluate the clinical features of INVM in children. Methods : The medical records of 10 patients with INVM were reviewed. We analyzed the clinical manifestations, hemodynamics, pattern of inheritance, and long-term prognosis of INVM in children. Results : Age at diagnosis was $45{\pm}53months$(1 day-14 years) with follow-up lasting as long as 78 months. Most INVM was asymptomatic on diagnosis. Associated cardiac anomalies were noted in six patients(ventricualr or atrial septal defect, patent ductus arteriosus with mitral valve prolapse, or mitral valve cleft). Depressed or flat changes of T wave in lead II, III and aVF were observed on electrocardiography. Various arrhythmia including WPW syndrome with paroxysmal supraventricular tachycardia, third-degree atrioventricular block, and familial sick sinus node dysfuction were observed. The degree of trabeculation in INVM was significantly prominent from level of mitral valve to apex compared to age-matched control. Familial recurrences were noted in two patients. The systolic function of the left ventricle was decreased in 20% of patients during the follow-up period, but systemic embolism or ventricular tachycardia was not observed. Conclusion : INVM is not a rare disorder. The cardiac function may be deteriorated in children as well as adults during long-term follow up. Thus early diagnosis and long-term follow-up must be done. So, the nation-wide multicenter clinical study would be mandatory to evaluate the incidence, long-term prognosis, and establishment of objective diagnostic criteria of INVM.

• Clinical and Experimental Pediatrics
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• v.45 no.11
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• pp.1389-1396
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• 2002

Purpose : This study was done to analyze the changes in the clinical conditions and the diagnosis of hypertrophic pyloric stenosis. Methods : We report a retrospective clinical analysis of 39 patients with hypertrophic pyloric stenosis from Jan. 1992 to Aug. 2001. The age and sex distribution, family and birth history, clinical symptoms, the ultrasonographic and the operative sizes of pyloric canals were compared. Results : The body weight was below the 3 percentile at admission in eight cases(20.5%). "Olive like mass" in right upper quadrant was palpated during physical examination in 23 cases(59%) and gastric peristaltic wave observed in six cases(15%). The ultrasonographic measurements showed that the pyloric muscle thickness to be $4.95{\pm}0.99mm$($mean{\pm}SD$), pyloric diameter $14.42{\pm}2.64mm$, and pyloric length $20.17{\pm}3.92mm$. Fredet-Ramstedt pyloromyotomy was employed in all cases. The operative measurements of the pyloric muscle thickness was $5.11{\pm}1.01mm$, pyloric diameter $15.01{\pm}2.47mm$, and pyloric length $22.32{\pm}3.43mm$. Conclusion : There was no significant difference between the ultrasonographic and operative measurements. Currently, the hypertrophic pyloric stenosis patients showed lesser clinical hallmarks of the disease. The earlier diagnosis using imaging studies before development of significant metabolic abnormalities is becoming an important factor that change the future outcomes of hypertrophic pyloric stenosis.

• The Journal of Engineering Geology
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• v.23 no.3
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• pp.201-216
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• 2013

Ground penetrating radar (GPR) surveys were conducted in a sand tank model in a laboratory and at an alluvial field site to detect the groundwater table and to investigate the influence of saturation on GPR response in the unsaturated zone. In the sand tank model, the groundwater table and saturation in the sand layer were altered by injecting water, which was then drained by a valve inserted into the bottom of the tank. GPR vertical reflection profile (VRP) data were obtained in the sand tank model for rising and lowering of the groundwater table to estimate the groundwater table and saturation. Results of the lab-scale model provide information on the sensitivity of GPR signals to changes in the water content and in the groundwater table. GPR wave velocities in the vadose zone are controlled mainly by variations in water content (increased travel time is interpreted as an increase in saturation). At the field site, VRP data were collected to a depth of 220 m to estimate the groundwater table at an alluvial site near the Nakdong river at Iryong-ri, Haman-gun, South Korea. Results of the field survey indicate that under saturated conditions, the first reflector of the GPR is indicative of the capillary fringe and not the actual groundwater table. To measure the groundwater table more accurately, we performed a GPR survey using the common mid-point (CMP) method in the vicinity of well-3, and sunk a well to check the groundwater table. The resultant CMP data revealed reflective events from the capillary fringe and groundwater table showing hyperbolic patterns. The normal moveout correction was applied to evaluate the velocity of the GPR, which improved the accuracy of saturation and groundwater table information at depth. The GPR results show that the saturation information, including the groundwater table, is useful in assessing the hydrogeologic properties of the vadose zone in the field.

• Journal of Chest Surgery
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• v.31 no.1
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• pp.20-27
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• 1998

It is well known that troponin T(below TnT) is present in the myocardial cells and released during myocardial damage, so it`s very specific enzyme to myocardium. Availability of cardiac specific TnT in assessing perioperatively myocardial damage was evaluated from 34 open heart surgery patients. They consisted of 11 ischemic heart, 13 acquired valvular heart and 10 congenital heart cases. Patients were divided into two groups, group A(patients with myocardial damage) and group B(patients without myocardial damage), according to the symptom of chest pain suspecting angina and the ECG findings of ST segment and T wave changes which show myocardial ischemia and injury. Serum TnT levels were measured by enzyme immunoassay method preoperatively, immediately postoperatively, postoperative day 1, day 2, day 3, and day 7. We observed and analyzed the changes of serum TnT levels in two groups and compared the serum TnT levels with CK-MB levels measured at the same time. In group A, serum TnT levels showed 1.37$\pm$0.26$\mu$g/L, 3.16$\pm$0.66$\mu$g/L, 2.39$\pm$0.74$\mu$g/L, 2.49$\pm$0.76$\mu$g/L, and 1.23$\pm$0.60$\mu$g/L, immediate postoperatively, postoperatively day1, day2, day3, and day7, respectively. It was observed there were significant differences compared with those of group B(0.38$\pm$0.04$\mu$g/L, 0.34$\pm$0.05$\mu$g/L, 0.25$\pm$0.03$\mu$g/L, 0.24$\pm$0.04$\mu$g/L, and 0.11$\pm$0.03$\mu$g/L) during identical periods(P<0.01). Serum CK-MB level in group A significantly elevated to 145.04$\pm$35.08 IU/L on the postoperative day 1 compared to group B(31.28$\pm$5.87 IU/L, P<0.05), However, it stiffly decreased from day 2 and returned to preoperative level at day 3. When serum TnT level more than 1.0$\mu$g/L is thought to reflect myocardial damage, serum TnT had 100% of sensitivity and 87% of specificity in diagnosing the postoperative myocardial damage(p<0.01). I conclusion, serum TnT levels increased significantly at very early stage of myocardial damage and persisted much longer period than CK-MB. This suggests that serum TnT has more advantage and availability in assessing the perioperatively myocardial damage than any other tests.