• Advances in pediatric surgery
• /
• 제4권1호
• /
• pp.27-33
• /
• 1998

Of 72 patients with vitelline duct and vessel remnants, 45 (62.5 %) had symptomatic lesions. The mean age of the patients was 27.9 months. Males predominated (4.6 : 1). There were 22 cases of Meckel's diverticulum, 6 of Meckel's diverticulum attatched to the umbilicus with a fibrous band, 6 cases of patent vitelline duct, 5 cases of vitelline artery remnants as a fibrous band and 2 cases each of umbilical sinus and polyp, and vitelline cyst. Twenty-three patients (51 %) presented with intestinal obstruction, 6(13 %) with rectal bleeding, 4(9 %) with perforated Meckel's diverticulum, 5 with intestinal juice drainage through umbilicus, 5 with umbilical lesions, 1 with abdominal mass, and 1 with sepsis. Intestinal obstruction due to fibrous band developed during infancy(average age; 4.6 months). Seventeen asymptomatic Meckel's diverticulum, 8 obliterated vitelline artery remnants and 1 vitelline vein remnant as fibrous band, and 1 vitelline cyst were found incidentally at laparotomy. About 82 % of the complicated Meckel's diverticulum presented in infants and children less than 4 years of age.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2000년도 전력전자학술대회 논문집
• /
• pp.70-73
• /
• 2000

In this paper we conducted research about the speaker's acoustic characteristics by the condition of the duct. It is expanding the bass ton play frequency as interfere two frequencies each other which originate from the speaker's back and front side using duct as attach the duct of round shaped or square at the encloser. This is not making of bass ton range using interference,. The structure of the duct which using the experiment is round shape. And we confirmed that can expand the limit of bass ton play as compare the actual experimental wave that after simulation of play frequency range as lenth change

• 한국원자력학회:학술대회논문집
• /
• 한국원자력학회 1997년도 추계학술발표회논문집(1)
• /
• pp.451-456
• /
• 1997

Temperature distribution measurements in the mockup apparatus of reactor vessel were performed to determine the effective thermal conductivity of porous media with different geometry and to obtain the experimental data for the heat transfer processes by natural convection occurring in the air duct. The temperature distributions at four separated sections with different arrangements of porous media have different slopes according to the geometrical configuration. From the measured temperature distribution, effective thermal conductivity have been derived using the least square fitting method. The test at air duct was performed to the high heat removal at 3.4kW/$m^2$ by the natural convection from the outer wall to the air. And also the temperature distributions in the air duct agree well with the 1/7th power-law turbulent temperature distribution. The obtained heat transfer data have been compared with the Shin's and Sieger's correlations.

• 한국간담췌외과학회지
• /
• 제27권2호
• /
• pp.220-225
• /
• 2023

Congenital duplication of the extrahepatic bile duct (DEBD) is an unusual anomaly of the biliary system. It occurs due to inability of the embryological duplex biliary system to regress. DEBD has various subtypes depending on the morphology and opening of the aberrant common bile duct. It can have distinct complications. We encountered a 38-year-old lady who experienced pain in the right upper abdomen along with a low-grade fever. Magnetic resonance cholangiopancreatography revealed DEBD with multiple calculi in the right hepatic duct (ductolithiasis) and joining of the right hepatic duct with the left hepatic duct in the intrapancreatic region. Endoscopic retrograde cholangiography failed to clear the calculi from the right duct. They were then managed by common bile duct exploration and roux-en-Y right hepaticojejunostomy for biliary drainage. Her postoperative period was uneventful. She is currently doing well after three months of follow-up. Hence, a proper preoperative delineation of such rare anomalies is essential. It could avoid inadvertent injury to the bile duct and operative complications.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1992년도 하계학술대회 논문집 A
• /
• pp.299-301
• /
• 1992

The adaptive active noise control algorithm for duct noise attenuation is considered. A new algorithm to estimate the secondary path transfer function using multiple models is presented. The computational burden of the proposed algorithm is much smaller than the existing methods, so it could be applied to the multi-channel cases. Computer simulations were done to show the effectiveness of the proposed algorithm in a duct case.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2010년도 춘계학술대회 논문집
• /
• pp.942-946
• /
• 2010

As the major sources of interior noise of train at running condition are the wheel/rail contact noise, the traction motor's noise and the driving gear's noise and these noise sources are transmitted through the car body, the noises of HVAC and air duct can be ignored. But the interior noise of train at standstill condition is decided by HVAC's noise and noise from the diffuser through the air duct. the interior noise prediction of train at standstill condition should be performed considering the shape of air duct, the air velocity and noise reduction property inside the air duct. But it is hard to estimate the interior noise level by the numerical method. Therefore train maker predict the interior noise level using The commercial noise prediction program. This paper introduce the noise prediction method of the train at standstill condition using the commercial program appling the ray tracing method and statistical energy analysis.

• 설비공학논문집
• /
• 제7권2호
• /
• pp.217-224
• /
• 1995

The effects of duct inlet conditions on fan characteristics and upper wind velocity fields were investigated for two kinds of impellers. As the duct inlet condition, the relative positions between duct inlet and fan impeller and the size of baffle plate mounted on a duct inlet were selected. The 3-dimensional velocity components in flow fields were measured by a 5-holes pitot tube. From the results of measurements, it was found that the size of baffle plate scarecely effect on upper wind flow fields and characteristics of fan. It was also confirmed that the upper wind velocity distributions can be estimated by the potential flow field with large baffle plate at duct inlet.

• Archives of Plastic Surgery
• /
• 제49권4호
• /
• pp.523-526
• /
• 2022

Salivary duct carcinoma is a rare malignant salivary gland tumor that mainly has solid features. When it occurs in the parotid gland, it can invade the facial nerve and cause facial nerve paralysis. However, in our case, the salivary duct carcinoma exhibited cystic features on computed tomographic imaging, and the facial nerve passed through the cyst. Total parotidectomy with level-I to -III dissections was performed and nerve passing through the tumor was sacrificed. The patient received postoperative radiotherapy and was clinically and radiologically followed-up for every 3 months. Recurrence or distant metastasis was not reported. To the best of our knowledge, this is the first case involving a salivary duct carcinoma with cystic features and facial nerve invasion. Here, we report a first case of cystic salivary duct carcinoma of the parotid gland which uncommonly undergo cystic change and penetrated by facial nerve and successfully resected without causing facial nerve injury.

• 융복합기술연구소 논문집
• /
• 제5권2호
• /
• pp.27-32
• /
• 2015

Air intakes are an essential component of aircraft engines. They are mainly used to offer uniform airflows to engine faces. Fighter aircraft have to mask the engine face inside the fuselage in order to reduce the Radar Cross Section(RCS). Therefore, offset intakes like a S-Duct are one of promising components for this purpose. During a fight, it is unavoidable that the flow will enter the intakes at some face angles other than zero. In this case, the performance of the aircraft engine will be influenced to the angle of incidence. In this study, the CFD analysis of the semi-circular S-Duct with AR(0.5,0) is performed to investigate the influence of the angle of incidence on the performance of the S-Duct using a distortion coefficient. To consider the adverse pressure gradient, a $k-{\omega}$ SST turbulence model is employed. The secondary flow and flow separation are observed for all computational cases. It is found that the positive incidence angle produces the best performances.

• Advances in pediatric surgery
• /
• 제15권1호
• /
• pp.11-17
• /
• 2009

Choledochal cyst is a congenital dilatation of the bile duct. Intrahepatic bile duct dilatation of type IVa by Todani's classification at the time of diagnosis resolved spontaneously after cyst excision and hepaticojejunostomy in many cases. It should be distinguished from the true cystic dilatation of the intrahepatic ducts, which tends to persist, albeit after some regression. We therefore studied postoperative intrahepatic duct dilatation changes in choledochal cyst. A total of seventy-six choledochal cysts were managed at the Division of Pediatric Surgery, Department of Surgery, Samsung Medical Center from May 1995 to December 2005. The ratio of males to females was 1:2.8. Preoperative radiologic diagnosis by Todani's classification was Type I (n=52, 68.4 %), II (n=1, 1.3 %), IVa (n=23, 30.3 %). Among fifty-five patients with intrahepatic bile duct dilatation we were able to follow up forty-eight by ultrasonography. Twenty-two patients were type IVa, and twenty-six patients were type I and showed intrahepatic duct dilatation. Mean follow-up duration was 35.3 months (9~105 months). Complete regression of dilated intrahepatic duct was observed in fifteen patients of type IVa and twenty-four patients of type I. Incomplete regression of dilated intrahepatic duct was observed in six patients in type IVa and two patients in type I. Only one patient in type IVa showed no change in ductal dilatation during a follow-up period of 15 months. We conclude that true type IVa is much less frequent than what was diagnosed preoperatively by imaging study. Therefore in type IVa patients who are diagnosed preoperatively the decision to perform liver resection should be carefully considered. Postoperative long term follow up of choledochal cyst with intrahepatic bile duct dilation is needed.