• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.513-515
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• 2022

Manufacturing data collected using IoT devices in a smart factory environment is generally reliable except for noises caused by external factors. However, unlike manufacturing data that is collected mechanically, process data manually recorded by field-workers can cause problems such as the misspelled entries or the missing entries. Therefore, process data must be validated before being used as training data for artificial intelligence models. In this paper, based on the fact that which is a linear relationship between the power consumption of the MCT machine and the production of the product recorded by the field-workers, we detect anomalous records of the workers using robust linear regression.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.10a
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• pp.619-622
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• 2004

For recent years, hacking is in the trends of making excessive traffic unnecessarily to obstruct the service by getting a system's performance down. And we can also see systems paralyzed in service ability due to the flash crowds of normal traffic to a popular website. This is an important problem certainly solved in the point of QoS guarantee for the clients. It is known that the former is DDoS(Distributed Denial of Service) attack and the latter is FE(Flash Event). These two are samely anomalous traffic because these make excessive congestion on the network or system and downgrade the system's service ability. In this paper, we propose a scheme for protecting the system against anomalous traffic and for guaranteeing the QoS. For this, a server records and maintains the information of clients accessed more than one time before when it is in normal condition. When it falls into the congestion, the records are used for filtering the spoofed IP. We send and receive the ICMP request/reply packet to know whether the IP is spoofed. And we also propose for applying the object spliting of CDN to guarantee the QoS in the initial FE situation.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.17 no.3
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• pp.170-177
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• 2014

Purpose: Choledochal cyst is a cystic dilatation of common bile duct. Although the etiology is presently uncertain, anomalous pancreaticobiliary ductal union (APBDU) is thought to be a major etiology of choledochal cyst. In this study, we analyzed the clinical and anatomical characteristics and pathologies of patients diagnosed with choledochal cyst in a single institute for 25 years. Methods: A total of 113 patients, diagnosed with choledochal cyst and who received an operation in Severance Children's Hospital from January 1988 to May 2013, were included. Medical records were reviewed, including clinical and demographic data, surgical procedures. Abdominal ultrasonography, magnetic resonance cholangiopancreatography, and intraoperative cholangiography were used as diagnostic tools for evaluation and classification of choledochal cyst and the presence of anomalous pancreaticobiliary ductal union. Todani's classification, and relationship between APBDU and surgical pathology. Results: Among 113 patients, 77 patients (68.1%) presented symptoms such as hepatitis, pancreatitis and/or cholecystitis. Eighty three patients (73.5%) had APBDU, and 94 patients (83.2%) showed inflammatory pathologic changes. APBDU, pathologic inflammation, and serological abnormalities such as hepatitis or pancreatitis showed a statistically significant correlation to one another. Conclusion: APBDU is thought to be one of the etiologic factors of choledochal cyst. It is related to the inflammatory changes in bile duct that can lead to the cystic dilatation.

• Journal of Chest Surgery
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• v.39 no.1 s.258
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• pp.12-17
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• 2006

Background: Circulatory arrest under deep hypothermia is an important auxiliary means for surgical correction of total anomalous pulmonary venous connection (TAPVC), However, cardiac operations under deep hypothermic circulatory arrest are associated with the risk of post-arrest neurologic abnormalities. The purpose of this study is to evaluate the results of the surgical correction of total anomalous pulmonary venous connection without the total circulatory arrest. Materiai and Method: Between April 2000 and October 2004, hospital records of 10 patients were reviewed retrospectively. Result: The locations for abnormal anatomical connections were supracardiac in 7 cases, cardiac in 1 case, and infracardiac in 2 cases. The mean cardiopulmonary bypass time and aorta cross clamp time were 116.8$\pm$40.7 and 69.5$\pm$24.1 minutes. There was no surgical mortality. Postoperative complications were post-repair pulmonary venous stenosis in 1 case, pneumonia in 1, pneumothorax in 1, wound infection in 1,and diaphragmatic paralysis in 1. All patients without pulmonary venous stenosis were in NYHA class I at mean follow-up of 16.6 months (3$\∼$49 months) Conclusion: We could obtain excellent results by repair without the total circulatory arrest for total anomalous pulmonary venous connection.

• Geophysics and Geophysical Exploration
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• v.8 no.1
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• pp.104-111
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• 2005

Dmitri Donskoi, the Russian cruiser launched in 1883, is known to have sunk near Ulleung Island (East Sea, Korea) on May 29, 1905, while it was participating in the Russo-Japanese War. In order to find this ship, information about its possible location was obtained from Russian and Japanese maritime historical records. The supposed location of the ship was identified, and we conducted a five-year geophysical survey from 1999 to 2003. A reconnaissance three-dimensional topographic survey of the sea floor was carried out using multi-beam echo sounder, marine magnetometer, and side-scan sonar. An anomalous body identified through the initial reconnaissance survey was identified by a detailed survey using a remotely operated vehicle, deep-sea camera, and the mini-submarine Pathfinder. Interpretation of the acquired data showed that the ship is hanging on the side of a channel, at the bottom of the sea 400 m below sea level. The location is about 2 km from Port Jeodong, Uleung Island. We discovered 152 mm naval guns and other war materiel still attached to the hull of the ship. In addition, the remnants of the steering gear and other machinery that were burnt during the final action were found near the hull. Strong magnetic fields, resulting from the presence of volcanic rocks in the survey area, affected the resolution of the magnetic data gathered; as a result, we could not locate the ship reliably using the magnetic method. Severe sea floor topography in the gully around the hull gave rise to diffuse reflections in the side-scan sonar data, and this prevented us from identifying the anomalous body with the side-scan sonar technique. However, the sea-floor image obtained from the multi-bean echo sounder was very useful in verifying the location of the ship.

• Journal of Chest Surgery
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• v.39 no.1 s.258
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• pp.18-27
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• 2006

Background: Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital anomaly, but is one of the most common causes of myocardial ischemia which would result in high mortality within the first year of life. This is our early result of the surgical management for these patients. Material and Method: From June 1989 to July 2003, 6 patients with ALCAPA and one patient with ARCAPA (Anomalous origin of the Right coronary artery from the pulmonary artery) underwent surgical repair. We have reviewed the all medical records, electrocardiogram, chest X-ray and echocardiography retrospectively. Result: Three of the patients were boys and four were girls. The median age at the operation was 5.4 months (Range: 3$\∼$33 months). The average body weight of at the operation was 6.7 kg (Range: 3.7$\∼$11.3 kg). A mean follow up period was 18 months. Only 3 patients were initially diagnosed as ALCAPA. And 3 patients had moderate mitral regurgitation. Immediate coronary artery reimplantation on diagnosis with the aim of restoring a two-coronary system circulation was done. The average bypass time was 114$\pm$37 minutes, and the average aortic cross clamping time was 55$\pm$22 minutes. The average stay of intensive care unit was 5$\pm$3 days, the mean mechanical ventilator time was 38$\pm$45 hours and the hospital stay after operation was 12$\pm$5 days. There were significant improvements in electrocardiogram and chest X-ray of the all patients except one late death patient. The ventricular function showed almost normal recovery after operation; the EF (Ejection Fraction) increased from 41.2$\pm$ 10.3$\%$ to 60.5$\pm$ 15.8$\%$ within 1 month and to 59.8$\pm$13.9$\%$ within 1 year after operation, the SF (Shortening Fraction) increased from 23.6$\pm$4.7$\%$ to 38.6$\pm$8.4$\%$ within 1 month and to 37.4$\pm$7.9$\%$ within 1 year after operation, LVEDDI (Left Ventricular End-diastolic Dimension Index) decreased from 100.8$\pm$25.6 mm/$m^{2}$ to 90.3$\pm$ 19.2 mm/$m^{2}$ within f month and to 79.3$\pm$ 15.8 mm/$m^{2}$ within 1 year after operation. Concomitant mitral repair was done in two patients with anterior mitral leaflet prolapse. In every patient, mitral valve showed less than mild regurgitation during follow up. One late death occurred in which patient Dor procedure was applied 10 months after initial operation due to the dilated cardiomyopathy Conclusion: In the management of this rare and could be fatal Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA), early suspicion and correct diagnosis is of most important. But, after diagnosis, immediate restoration of 2 coronary systems could result in good outcome.

• Economic and Environmental Geology
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• v.18 no.2
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• pp.151-157
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• 1985

Events detected by the KIER microearthquake network operated in the Southern Part of Korea for 265 days in 1982~1984 were reviewed, and some of them were identified to be a dynamite explosion from several construction sites. The purpose of the present work is to determine the crustal structure of the Southern Korea using the time-destance data obtained from such explosion seismic records. The time·distance data can be well explained by a crustal model composed of four horizontal layers of which thickness, p and s-wave velocity ($V_p$ and $V_s$) are characterized as follows. 1st layer (surface) ; 0~2km, $V_p=5.5km/sec$, $V_s=3.3km/sec$ 2nd layer (upper crust) ; 2~15km, $V_p=6.0km/sec$, $V_s=3.5km/sec$ 3rd layer (lower crust) ; 15~29km, $V_p=6.6km/sec$, $V_s=3.7km/sec$ 4th layer (upper mantle) ; 29km~ , $V_p=7.7km/sec$, $V_s=4.3km/sec$ The relatively shallow crust·mantle boundary and low $P_n$ velocity compared with the mean values for stable intraplate region are noteworthy. Supposedely, it is responsible for the high heat flow in the South-eastern Korea or an anomalous subterranean mantle. The mean $V_p/V_s$ ratio calculated from the relation between p-wave arrival and s-p arrival times appears to be 1.735 which is nearly equivalent to the elastic medium of ${\lambda}={\mu}$. However, the ratio tends to be slightly larger with the depth. The ratio is rather high compared with that of the adjacent Japanese Island, and the fact suggests that the underlying crust and upper mantle in this region are more ductile and hence the earthquake occurrences are apt to be interrupted. As an alternative curstal model, a seismic velocity structure in which velocities are successively increased with the depth is also proposed by the inversion of the time·distance data. With the velocity profile, it is possible to calculate a travel time table which is appropriate to determine the earthquake parameters for the local events.

• Journal of Chest Surgery
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• v.32 no.6
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• pp.510-517
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• 1999

Background: Total anomalous pulmonary venous connection (TAPVC) is still one of the more challenging congenital heart defects in newborns and young infants. The purpose of the study is to evaluate the early and midterm results of the surgical corrections for patients in early infancy with isolated TAPVC. Material and Method: Hospital records of 15 consecutive patients in early infancy (January 1993 to August 1998) were retrospectively reviewed. There were 8 boys and 7 girls whose ages ranged from 4 days to 3.5 months (median age 22 days). Their body weight ranged from 1.75 kg to 4.9 kg (mean 3.54 kg). The abnormal anatomical connections were supracardiac in 11, cardiac in 3, and infracardiac in 1. In 6 patients (40%), the pulmonary venous drainage was obstructive. Total circulatory arrest was used in 13 patients. Anastomosis between the common pulmonary vein and the left atrium was performed with a continuous suture technique using a fine nonabsorbable polypropylene suture through a lateral approach behind the right atrium. Result: There was one hospital death (6.5%) caused by a sepsis 17 days after the operation in a neonate who had supracardiac drainage and was dependent on a ventilator preoperatively. There were 2 late deaths. One died sudde`nly of an unknown cause at home 2.5 years after the operation and the other died of a recurrent pulmonary hypertension 3 months after the reoperation due to pulmonary venous obstruction (PVO). Two patients required reoperations because of PVO 5 months and 10 months respectively after the initial operation. Of these patients, one patient is alive at the present time with persistent pulmonary hypertension. All survivors without postoperative PVO (78.6%) were in NYHA functional class I at mean follow-up of 25.8 months (0.5∼67 months). Conclusion: Surgical correction of TAPVC in early infancy can be performed at low risk. However, there were 2 postoperative PVOs (14.3%) which had bad results. The survivors without postoperative PVO had excellent functional status.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.3
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• pp.249-257
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• 2017

Filtering the data for travel time records obtained from DSRC probes is essential for a better estimation of the link travel time. This study addresses the major deficiency in the performance of TRANSGUIDE in removing anomalous data. This algorithm is unable to handle unstable traffic flow conditions for certain time intervals, where fluctuations are observed. In this regard, this study proposes an algorithm that is capable of overcoming the weaknesses of TRANSGUIDE. If TRANSGUIDE fails to validate sufficient number of observations inside one time interval, another process specifies a new validity range based on the median absolute deviation (MAD), a common statistical approach. The proposed algorithm suggests the parameters, ${\alpha}$ and ${\beta}$, to consider the maximum allowed outlier within a one-time interval to respond to certain traffic flow conditions. The parameter estimation relies on historical data because it needs to be updated frequently. To test the proposed algorithm, the DSRC probe travel time data were collected from a multilane highway road section. Calibration of the model was performed by statistical data analysis through using cumulative relative frequency. The qualitative evaluation shows satisfactory performance. The proposed model overcomes the deficiency associated with the rapid change in travel time.

• Advances in pediatric surgery
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• v.16 no.2
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• pp.154-161
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• 2010

Pulmonary sequestration (PS) is a rare congenital malformation of the lower respiratory tract. The anomaly is characterized by absence of communication with the tracheobronchial tree and isolated blood supply from an anomalous systemic vessels. With the utilization of antenatal ultrasound, the diagnosis of asymptomatic neonatal PS has increased. Treatment options include observation, arterial embolization and surgical resection. The aim of the present study is to review the clinical course of PS and to share our experience with thoracoscopic resection. A total of 96 patients with PS were treated at Asan Children's Hospital between 1999 and 2010. The diagnosis of PS was established by CT in the cases managed by observation or embolization, and by tissue pathology in the surgical cases. Medical records and radiographic images were retrospectively reviewed. Thirty-nine patients were managed by embolization and 30 patients by surgery. The remaining 27 patients have been under observation without any procedures. Among 27 observation patients, 1 patient regressed completely and 10 patients were lost to follow up. Of the 39 embolizations patients, 2 had their lesion regress and sepsis was suspected after embolization. In 1 patient, the microcoil migrated to the iliac artery during the embolization procedure, and another patient developed renal abscess caused by renal artery embolization. Among 30 surgical cases, resection by thoracotomy was performed in 27 at the Department of Thoracic Surgery, and thoracoscopic resection in 3 at the Division of Pediatric Sugery. Only one wound complication ocurred. We conclud that surgical excision should be recommended for pulmonary sequestration, whether the sequestration is symptomatic or not because of the risk of infection, the low rate of natural regress, poor compliance, severe complications after embolization, and to exclude other pathology. In summary, thoracoscopic resection of the pulmonary sequestration is feasible, efficacious, safe and cosmetically superior even in neonatal period.