• Advances in pediatric surgery
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• v.10 no.2
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• pp.131-135
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• 2004

The purpose of this retrospective study was to evaluate the effects of diagnostic sonography in pediatric patients with inguinal hernias. The patients were classified into two groups. Group A included the patients who had been operated upon for inguinal hernia in 1980's, when diagnostic sonography was not available. Group B included the patients, operated upon for inguinal hernia from 2001 to 2002, when inguinal sonography was employed to detect potential bilateral hernias. The age distribution, sex ratio, laterality, bilaterality, and concomitant symptoms were compared between group A and group B. There were 296 cases in group A and 377 cases in group B. The prevalent age group was from 1 to 5 years. There was no difference in age group distribution between both groups. The male to female ratio was 5.3:1 in group A and 3.5:1 in group B. The ratio of unilateral to bilateral hernia was 5:1 in group A and 3:1 in group B. In cases with a unilateral hernia, the ratio of right to left was 1.5:1 in group A and 1.8:1 in group B. In cases with bilateral hernia, the simultaneous bilateral hernia was 33 cases (67.4 %) in group A and 75 cases (80.6 %) in group B. The sequential bilateral hernia was 16 cases (32.7 %) in group A and 18 cases (19.4 %) in group B. Although the ratio of bilateral hernia was increased in group B, the portion of the sequential bilateral hernia was significantly decreased in group B. In conclusion, there were no differences in the age distribution and the laterality between group A and B. The ratio of female patients and the incidence of bilateral hernia were increased in group B even though the portion of the sequential bilateral hernia was decreased. This result shows that the preoperative inguinal sonography in unilateral hernia with potential bilateral hernia is useful in early detection of the sequential contralateral hernia.

• Journal of Chest Surgery
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• v.21 no.6
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• pp.970-978
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• 1988

There is tendency of increasing number and decreasing age of patients who are indicated for Rastelli operation for their cyanotic congenital heart disease. So there is the need to find the criterion which saves the patients from early postoperative hemodynamic disturbances. We reviewed the 26 patients who had been performed Rastelli operation at Seoul national University Hospital from January 1981 to June 1988. mean age of the patients was 7.8*3.4 years[range 2.5-15years], mean body surface area[BSA] 0.79*0.25m2[range 0.49-1.51m2] and mean hematocrit 57.95*12%[range 48-80%]. We divided these patients into survived group and died group before postoperative 72 hours, and analyzed preoperative arterial oxygen saturation[SaO2], the ratio of diameter of right pulmonary artery to ascending aorta[RPA/AA], the ratio of both right and left pulmonary artery diameter to descending thoracic aorta[RPA+LPA/DTA], pulmonary artery index[PA index], cardiopulmonary bypass time, aorta cross-clamping time, postoperative perfusion state and total amount of dopamine infused postoperatively. The results showed that RPA+LPA/DTA and PA index were statistically significant factors to influence early postoperative cardiac death rate[P< 0.05]. Especially there were good linear correlations between PA index[X] and peripheral perfusion index[Y][Y= - 1.15+0.02 X, r=0.86, P<0.01]and between PA index[X] and total amount of dopamine infused before postoperative 72 hours[mg/kg, Y][Y=61.94 - 0.15 X, r=-0.80, P < 0.01]. Also there were tendencies that the higher RPA+LPA/DTA[Y], the better peripheral perfusion [X] and the lower need of dopamine[X], but no statistical significance.[Y=0.78+1.60 X, r =0. 49, P >0.05] And the discriminate analysis showed that patients with PA index over 221 mm2/BSA could undergo correction with 25 per cent of error rate. In conclusion, early postoperative hemodynamic states could be predicted by preoperatively measured PA index, and which can be used as a criterion for Rastelli operation performed on cyanotic congenital heart disease.

• Journal of Yeungnam Medical Science
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• v.7 no.2
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• pp.141-149
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• 1990

The authors conducted a clinical observation of 55 cases of solitary pulmonary nodules at Yeungnam University Hospital from June 1986 to October 1990, and the following results were obtained : 1. The age distribution was ranged from 18 to 77 years, and the male-to-female ratio was 1.8:1. 2. Among 55 cases of nodules, 28 cases were benign and 27 cases were malignant nodules, and of malignant nodules, the primary lung cancer was 23 cases and of benign nodules, 18 cases were tuberculoma. 3. 23 cases (41.8%) was asymptomatic and the other 32 cases were symptomatic; chest pain 12 cases, hemoptysis; 8 cases, cough; 8 cases and dyspnea; 4 cases. 4. The non-smoker-to-smoker ratio was 1:1.04, but among 23 smoker over 20 pack years, 14 cases were malignant nodules. 5. According to nodular size, there is no striking differences between benign and malignant nodules except 3-4cm sized nodules. 6. The lobar distribution of nodules, 35 cases were in the right lung (upper lobe; 14 cases, middle lobe; 11 cases, and lower lobe; 10 cases) and 20 cases were in the left lung(upper lobe; 9 cases, lower lobe; 11 cases), and the malignant nodules were most commonly observed in the right upper lung.

• Journal of Chest Surgery
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• v.17 no.3
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• pp.511-515
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• 1984

In this study, 213 cases of the spontaneous pneumothorax experienced at the department of thoracic and cardiovascular surgery, Chungnam National University Hospital during from April, 1977, till Dec, 1983 were reviewed. 1.Sex ratio of the studied patients was 7.19;1 showing high incidence male patients. The incidence according to the age group showed that 20.2%, 18.3% of the patients belong to the age group 6th, 5th decade respectively. 2.The etiologic factors were as follows, tuberculous origin in 50.2%, unknown origin in 28.2%, COPD in 3.3%, bullae in 8.5%. The site was right in 47.9% and left in 44.1%, bilateral in 8%. 3.The clinical symptoms were frequently dyspnea in 35%, chest pain in 27.5%. 4.The employed method of treatment were as follow, bed rest with oxygen inhalation in 1.9%, closed thoracostomy in 95.8%, open thoracotomy in 7.98%, which bullectomy was performed in 12 cases and pneumonectomy in 3 cases and lobectomy in 1 case and decortication with simple closure of bleb was performed in remaining 1 case. 5.The duration of closed thoracostomy was longer in tuberculosis, which average duration was 11.28 days. 6.The overall recurrent rate was 12.3%.

• Journal of Chest Surgery
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• v.23 no.6
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• pp.1213-1220
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• 1990

During the period of January 1979 to December 1988, 220 patients with empyema thoracis were treated in the department of Thoracic and Cardiovascular Surgery, Chonnam National University Medical School Hospital. There were 167 males[75.9%] and 53 females[24.1%] ranging from 18 days to 76 years of age. Occurrence ratio of left and right empyema was 1 : 1.9. The underlying pathologic lesions of empyema were pneumonia[30.9%], pulmonary tuberculosis[22.7%], chest trauma[8.6%] and postoperative complications. In bacteriologic study, staphylococcus, pseudomonas and streptococcus accounted for 26.4%, 11.8% and 9% respectively, and 25% were not identified. Surgical treatment modalities were thoracentesis[10 patients, 4.5%], closed thoracostomy[132, 60%], closed rib resection drainage[4.2, 6%], modified Eloesser’s operation[37, 16.8%], decortication[27, 12.3%], decortication with pulmonary resection[6, 2.7%], thoracoplasty[2, 0.9%], muscle flap closure [1, 0.5%], and staged pneumonectomy[1, 0.5%], The mortality rate was 2.3% and the complications were sepsis[9 patients]. acute renal failure[4], and paralytic ileus[3].

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.181.2-181
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• 2001

Stereo PACS (Picture Archiving and Communication System) is not available yet because of some limitations of medical stereo image software and viewing devices. As a stereo PACS viewer, we designed two functions. One is selecting and viewing a multiplexed stereo image directly, and the other is selecting a stereo pair image (left and right sides both) and merging the stereo pair image into a multiplexed image in software. For the medical image compression of 3-D stereo endoscopic images, we used JPEG and Wavelet compression and to determine an acceptable compression rate using PSNR (Peak Signal-to-Noise Ratio). As a result, we got the conclusion that medically acceptable image compression rate should have the PSNR of above about 40[dB] (JPEG (5:1), Wavelet (10:1)).

• Journal of International Academy of Physical Therapy Research
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• v.8 no.2
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• pp.1158-1162
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• 2017

The purpose of the study was to investigate the strength of sokinetic muscle by the position of a volleyball players. Analysis and comparison of shoulder dynamic stability will be conducted according to rotational movement of the shoulder during spiking and serving amongst the various positions. Fifty professional Korean female volleyball players (age: 20~30), all different positions - attacker (left and right), center, setter, and libero were The concentric peak torque, strength ration of the internal and external rotation of the shoulder girdle for both dominant and non-dominant arms. Firstly, there were significant differences found for the strength ratio between the setter and the other positions in the dominant arm. On a second note, there was a significant decrease in shoulder dynamic stabilization for both the attacker and center in the dominant arm. However, there were no significant differences for the setter or the libero. This study suggests that the isokinetic muscle strengths of the volleyball players are different from each other.

• Electrical & Electronic Materials
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• v.9 no.1
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• pp.24-29
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• 1996

A composite piezoelectric ceramic transducer is fabricated with three piezoelectric ceramic disk vibrators and two sheets of thin insulator. Its equivalent circuit is derived from the Mason's model of a thickness-driven piezoelectric vibrator. When the electric input near its fundamental resonance frequency is applied to the center vibrator and the output voltages across the left and the right vibrators are connected in series to the resistor loads, the load characteristics at resonance frequencies under the various resistor loads and the frequency characteristics near the resonance frequency without load are investigated. Furthermore, symbolic expressions for input impedances, voltage ratios, resonance frequencies, and bandwidths are derived. The data calculated from those symbolic expressions are agreed well with the measurement data.

• Steel and Composite Structures
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• v.31 no.3
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• pp.277-290
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• 2019

This paper investigates the parametric instability (PI) of multilayered composite conical shells (MLCCSs) under axial load periodically varying the time, using the first order shear deformation theory (FOSDT). The basic equations for the MLCCSs are derived and then the Galerkin method is used to obtain the ordinary differential equation of the motion. The equation of motion converted to the Mathieu-Hill type differential equation, in which the DI is examined employing the Bolotin's method. The expressions for left and right limits of dimensionless parametric instability regions (PIRs) of MLCCSs based on the FOSDT are obtained. Finally, the influence of various parameters; lay-up, shear deformations (SDs), aspect ratio, as well as loading factors on the borders of the PIRs are examined.

• Transactions of the Korean Society of Automotive Engineers
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• v.25 no.2
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• pp.242-249
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• 2017

In this study, the relationship between the shape of a passenger airbag and the possibility of injury is analyzed using the Taguchi method. The optimal shape combination is proposed for a design guideline that can reduce the possibility of injury to the dummy. The airbag FE model for analysis is obtained using a CAD system that can change the shape through several independent variables. The widths of the left / right, top / bottom, and back / forth direction of the airbag shape are set as the design factors, and the effect of the combination injury probability according to the shape is analyzed. The minimum geometric combinations are obtained using the orthogonal array method. The signal to noise ratio is calculated and the optimal shape combination is obtained through sensitivity analysis. The obtained optimal shape combination is compared with the possibility of injury of the initial airbag shape to confirm improved airbag performance.