• International Journal of Highway Engineering
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• v.11 no.2
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• pp.99-109
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• 2009

Fine-size exposed aggregate portland cement concrete pavements (FEACP) have surface texture of exposed aggregate by removing upper 2$\sim$3mm mortar of surface of which curing is delayed by using delay-setting agent. FEACPs have advantages of maintaining low-noise and adequate skid-resistance level during the performance period than general portland cement concrete pavements. It is necessary to ensure the durability environmental loading to prevent unexpected distress during the service life of FEACP. In the process of curing, volume change accompanied change in by moisture and temperature could be an important cause of crack in concrete to construct for successful FEACP, The use of chloride containing deicer may accelerate defects of concrete pavement, such as crack and scaling. This study aim to evaluate environmental loading resistance of FEACP, based on the estimation of shrinkage-crack-control-capability by moisture evaporation and scaling by deicer in freeze-thaw reaction.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.1
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• pp.1-9
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• 2018

Lambda wing type Unmanned Combat Aerial Vehicle(UCAV) which adopts Blended Wing Body(BWB) has relatively less drag and more stealth performance than conventional aircraft. However, Pitching moment is rapidly increased at a specific angle of attack affected by leading edge vortex due to leading edge sweep angle. Wind tunnel testing and numerical analysis were carried out with UCAV 1303 configuration on condition of 50 m/s of flow velocity, $-4^{\circ}{\sim}28^{\circ}$ of the range of angle-of-attack. The effect of wing twist for longitudinal stability at the various angles of attack was verified in this study. When negative twist is applied on the wing, Pitch-break was onset at higher angle of attack due to delayed flow separation on outboard of the wing. On the other hand, pitch-break was onset at lower angle of attack and lift-to-drag ratio was increased when positive twist is applied on the wing.

• Clinical and Experimental Pediatrics
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• v.45 no.4
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• pp.512-518
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• 2002

Purpose : Cerebral palsies are the most common and severe motor disabilities in childhood. There is currently increased interest in their occurrence and patterns of likely cause for a variety of reasons. Therefore, a retrospective study was carried out to understand the clinical features of cerebral palsy. Methods : A retrospective chart review was conducted of all children with cerebral palsy who were diagnosed at St. Benedict Hospital between March 1999 and March 2001. Results : Cerebral palsy patients were classified into 6 major groups. Of six groups, spastic diplegia is the most common type of cerebral palsy(55.3%). The risk factors of cerebral palsy were placenta previa(1 case), placenta abruption(1 case), cytomegalovirus infection(1 case), prematurity (53 cases), neonatal asphyxia(12 cases), dystocia(2 cases), breech delivery(1 case), multiple birth(5 cases), head trauma(3 cases), meningitis(2 cases) and unknown(26 cases). Among the 59 in the preterm group, 37 patients showed MR or CT images of periventricular leukomalacia. Among the 44 in the term group, 15 patients showed MR or CT images of atrophy. Among 103 patients, 29 patients(28.2%) had a seizure disorder. Conclusion : It is very importent to understand the clinical features and risk factors of cerebral palsy for physicians to diagnose and manage cerebral palsy patient.

• Journal of the Korea Concrete Institute
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• v.22 no.5
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• pp.703-710
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• 2010

Reinforced concrete beams of existing structure often encounter insufficient shear problems for various reasons. Application of steel plates is one of widely used methods for shear strengthening of reinforced concrete beams that are insufficient of shear capacity. This study presents test results on strengthening shear deficient RC beams by external bonding of vertical and diagonal slit type steel plates with anchor bolt. Test parameters are width, interval, angle and length of slits with anchor bolt. The purpose was to evaluate the failure modes and shear capacities for RC beams strengthened by various slit type steel plates with anchor bolt. The results showed that the slit type steel plate specimens strengthened by adhesive bonding and bolting failed in shear fracture modes at maximum load. Flexural crack first occurred on the tension face of beam and then inclined cracks occurred on the shear span. Finally, slit type steel plates strengthened by adhesive bonding and fastening bolts managed to delay abrupt debonding and didn't detach fully from main body of RC beam.

• Korean Journal of Cleft Lip And Palate
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• v.9 no.2
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• pp.93-100
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• 2006

Although the delayed type of rhinoplasty is currently acceptable in the correction of cleft lip and nasal deformity, Delaire tried to achieve the simultaneous nasolabial reconstruction and muscular rearrangement that affect the subsequent skeletal growth of the face. the anatomic muscular reconstruction can be achieved by making the anchorage of the nasolabial muscles of the cleft side to the nasal septum and muscles on the non-cleft side. Two cleft lip patients of 6 and 7 year-old without any previous operation history were treated with the functional cheilorhinoplasty. One patient with incomplete cleft lip underwent a cheiloplasty along with the rearrangement of orbicularis oris muscle. The other patient had a complete cleft lip and palate with accompanying nasal deformity, who underwent the functional cheilorhinoplasty with the reconstruction of anterior nasal base. All the operation was done under the general anesthesia and patients healed without any significant complications. In the incomplete case, the shapes of Cupid's bow was restored, and the length of columella was regained comparable to the non-affected side. In the complete cleft lip and palate case, the depressed nostril was reconstructed with acceptable symmetry by complete releasing of deformed alar cartilage undermined with a dissecting scissors. In summary, the functional repair of cleft lip and nose could be possible at the same time by using Delaire method. This method is effective to correct the primary nasolabial deformity, which results in the restoring favorable anatomy and its function.

• Clinical and Experimental Pediatrics
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• v.52 no.6
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• pp.674-679
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• 2009

Purpose : The authors aimed to analyze the long-term effects of treatments, especially external beam radiotherapy (EBRT), in bilateral retinoblastoma patients. Methods : This retrospective study analyzed the medical records of 22 bilateral retinoblastoma patients who were registered between October, 1987 and October, 1998 and followed-up for more than 10 years. They were treated by enucleation, EBRT, and systemic chemotherapy. Age at diagnosis, sex, delay prior to treatment, Reese-Ellsworth (RE) classification, and the local treatment modalities were analyzed in relation to recurrence-free survival (RFS) and complications. Results : Median age at diagnosis was 7.0 months (range 1.7-31.6 months). Leukocoria was the most common presenting feature. Two patients had a familial history. The RE classifications of the 44 eyes were group II in 4, III in 14, IV in 4, and V in 22. At the end of a median follow-up period of 141 months (range 55-218 months), 20 patients were alive. The 10-year ocular survival rate of the 44 eyes was $56.8{\pm}7.5%$. The 10-year RFS and ocular survival rate of the 29 eyes treated by combined EBRT and chemotherapy were 75.9% and 86.2%, respectively. Treatment delay (>3 months) was found to be related to higher risk of recurrence. Complications after EBRT were cataract, retinal detachment, phthisis bulbi, and facial asymmetry. No patient developed a second malignancy during the follow-up period. Conclusion : Early detection and prompt treatment can increase ocular survival rates. In addition, careful attention should be paid to possible long-term sequelae in these patients.

• Journal of the Korean Arthroscopy Society
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• v.3 no.2
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• pp.115-120
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• 1999

Purpose : After the total or partial meniscectomy of the lateral discoid meniscus, many patients complain the residual pain or the recurrent symptoms of the meniscus, and some of them need reoperation. We analyzed the causes of the reoperation after initial meniscectomy. Material & Method : Two hundred seventy three patients with the symptomatic lateral discoid meniscus were treated by arthroscopic meniscectomy between October, 1989 and September, 1998. Of the 273 patients, 69 patients were treated by total meniscectomy and 204 patients were treated by partial meniscectomy. The male to female sex ratio was 1:1.04, and the average of the age was 23.1 years old(from 4 to 59 years old). The reoperation was done in 8 patients, of which 1 was the case of total meniscectomy at the initial operation, and the rest 7 were the case of partial meniscectomy. Results : Of the 8 reoperations, 3 patients recurred the meniscal symptoms within the 3rd week after the initial operation, and 5 patients recurred beyond the 3rd week after the initial operation. Among the 3 patients of carly recurrence, 2 patients showed inadequate sizes of the remnant meniscus, and 1 patient showed posterolateral instability of the remained meniscus. Among the 5 patients of late recurrence, 3 patients showed rerupture of the meniscus, and 2 patients showed associated pathology of degenerative arthritis following osteochondritis dissecans. Conclusions : The reoperation rate after initial meniscectomy of the lateral discoid meniscus was higher in partial meniscectomy than total meniscectomy. During the operation of the lateral discoid meniscus, we must determine the adequate resectional margin, confirm the remnant meniscus by probing, and look for the associated pathologies.

• Journal of Chest Surgery
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• v.42 no.3
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• pp.350-354
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• 2009

Background: Complicated pleural space occupying lesions (SOL) have been treated by thoracentesis, closed thoracotomy drainage (CTD) or surgical intervention with using a video thoracosocpe or open thoracotomy depending on the extent of the disease. With the development of video assisted thoracoscopic surgery (VATS), VATS pleural adhesiolysis and decortication have revealed good results as compared to those for open thorcotomy. To assess the effectiveness of VATS pleural adhesiolysis and decortication, we retrospectively analyzed the medical record and radiologic findings of the patients with complicated pleural SOL and who were treated by this surgery. Material and Method: From May 1996 to April 2006, 64 patients (mean age: 41.8 years) with complicated pleural SOL underwent 65 VATS. To analyze the surgical outcome, we classified the postoperative findings on the simple chest X-rays into 4 classes as Class I: no or minimal pleural lesion, Class II: blunting of the cardiophrenic angle and mild pleural thickening, Class III: an elevated diaphgram or persistent lung collapse and Class IV: complicated or recurrent effusion. Result: Before VATS, the patients underwent the diagnostic or therapeutic procedures: single or repeat diagnostic tapping for 41, thoracoscotomy drainage for 11, pigtail catheter drainage for 10 and intrapleural fibrinolytics for 10. The mean duration between the onset of symptom and surgery was 18.4 days. There was neither mortality nor severe complications. The surgical outcomes were class 1 for 28, class 2 for 13, class 3 for 19 and class 4 for 5. There were statistically significant differences between the symptom duration and the classes, and between the operation time and the classes. Conclusion: VATS pleural adhesiolysis and decortication are effective, safe treatments for managing complicated pleural SOL, and an earlier operation is needed for obtaining a better surgical outcome.

• Journal of Chest Surgery
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• v.40 no.12
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• pp.837-842
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• 2007

Background: Closure of the ductus arteriosus is often delayed in premature infants, which creates a hemodynamically significant left to right shunt that exerts an adverse effect on the normal development and growth of these babies. We reviewed out experience on surgical closure of patent ductus arteriosus via axillary minithoracotomy in premature infants. Material and Method: From April 2002 to October 2006, 20 premature infants whose gestation was under 37 weeks underwent surgical closure of patent ductus arteriosus as a result of complications or contra-indications for the use of indomethacin. Their mean gestational age was 28.8+3.4 weeks, ranging from 25+3 to 34+6 weeks, and the average age at operation was $15.6{\pm}6.3$ days. The mean body weight at operation was $1,174{\pm}416\;g$, ranging from 680 to 2,100g; 16 infants were under 1,500 and 9 infants were under 1,000 g. The procedures were performed in the newborn intensive care unit via $2{\sim}3\;cm$ long axillary minithoracotomy with the infant in the lateral position with left arm abduction. The mean size of the patent ductus arteriosus was $3.8{\pm}0.3\;mm$. For the most part, the ductus was closed with clips; 2 infants in whom the ductus was ruptured while dissection was being performed underwent ductal division. Result: Ten of twelve infants who had been ventilator dependent preoperatively could be successfully weaned from the ventilator at a mean duration of 9.7 days after the operation. There was no procedure-related complication or death. Two infants eventually died of the conditions not related to the operation; one from sepsis at postoperative 131 days and the other from pneumonia at postoperative 41 days, respectively. Conclusion: Surgical closure of the patent ductus arteriosus improved the hemodynamic instability and so promoted the successful growth and normal development of premature infants. Considering the low surgical risk along with the reduced invasiveness, early and aggressive surgical intervention is highly recommended.

• Journal of Chest Surgery
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• v.30 no.2
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• pp.172-178
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• 1997

We present a etrospective analysis of arterial embolectomies performed at the Inje University Seoul Paik Hospital. During the period of March 1987 Feburary 1996 twenty-six patients underwent embolectomies, eighteen patients were male and eight patients were female, mean age of patients was 56.8 years. Rest pain was the chief complaint in 24 patients, the remaining two patients complained of long term history of claudication after recovery of acute symtoms. But only 10 patients had sensBrylmotor symtoms. Heart was the most common source of embolization and frequent predisposing factor of embolism was ischemic heart disease in 8 cases and valvular heart disease in 11 cases. The sites of embolization were upper extremities artery in 6 cases, saddle embolism in 2 cases, lower extremities artery in 18 cases and the most common site of embolism was femoral artery in 1 1 cases. Preoperative angiography was taken in the diagnosis and planning of the embolectomy in 1) patients while in the other patient p eoperative angiography was not taken. Only two cases were operated within the golden period of 6 hours and other cases were operated in more than 6 hours after embolization. In all patients, the Fogarty embolectomy catheter was used without bypass surgery via bachial ateriotomy in the embolism of upper extremities artery, bilateral groin approaches in the saddle embolism and transfemoral approach in the embolism of lower extremities artery. However 3 patients were re-operated via transpopliteal approach in the distal poplitiotibial embolism. Eighteen patients received perioperative anticoagulation therapy by heparin or fraxiparine and wafarin was used in 17 patients at the time of discharge and the indication of anticogulation was patients of valvular heat disease andfor atrial fibrillation, peripheral artery atherosclerosis and recurrent embolism. Postoperative results of the embolectomy were as follows: fouteen pateints had excellent results, five cases had symtom improvement after re-operation, B. K. amputation in 1 case who had severe atherosclerosis of lower extremities, recurrent embolism in 1 case and death in 2 cases the cause of death were acute renal failure and cerebral artery embolism, respectively. The complications of the embolectomy were reperfusion syndrome, pseudoaneurysm and intimal dissection in one case each. Conclusively the problems of embolism is delayed diagnosis and increasing number of old aged patient who had suffered from ischemic heart diease. Preoperative angiography was not always needed for embol ectomy. Selective anticoagulation therapy can decrease incidence of re-embolism. In the distal poplitiotibial embolism, embolectomy of tibial artery was difficult.