• International Journal of Fuzzy Logic and Intelligent Systems
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• v.15 no.2
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• pp.102-110
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• 2015

The main source of noise in computed tomography (CT) images is a quantum noise, which results from statistical fluctuations of X-ray quanta reaching the detector. This paper proposes a neural network (NN) based hybrid filter for removing quantum noise. The proposed filter consists of bilateral filters (BFs), a single or multiple neural edge enhancer(s) (NEE), and a neural filter (NF) to combine them. The BFs take into account the difference in value from the neighbors, to preserve edges while smoothing. The NEE is used to clearly enhance the desired edges from noisy images. The NF acts like a fusion operator, and attempts to construct an enhanced output image. Several measurements are used to evaluate the image quality, like the root mean square error (RMSE), the improvement in signal to noise ratio (ISNR), the standard deviation ratio (MSR), and the contrast to noise ratio (CNR). Also, the modulation transfer function (MTF) is used as a means of determining how well the edge structure is preserved. In terms of all those measurements and means, the proposed filter shows better performance than the guided filter, and the nonlocal means (NLM) filter. In addition, there is no severe restriction to select the number of inputs for the fusion operator differently from the neuro-fuzzy system. Therefore, without concerning too much about the filter selection for fusion, one could apply the proposed hybrid filter to various images with different modalities, once the corresponding noise characteristics are explored.

• Korean Journal of Otorhinolaryngology-Head and Neck Surgery
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• v.61 no.12
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• pp.697-701
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• 2018

Background and Objectives The aim of this study was to evaluate surgical completeness in endoscopic total thyroidectomy with central neck dissection via unilateral axillo-breast approach (UABA) compared with bilateral axillo-breast (BABA) and open approach (OA) by means of the radioactive iodine uptake (RAIU) ratio and thyroglobulin (Tg) of remnant thyroid. Subjects and Method From July 2010 to March 2013, 82 patients who had underwent total thyroidectomy with central neck dissection and postoperative radioactive iodine (RAI) ablation for papillary thyroid carcinoma were enrolled. Of these patients, 27 patients underwent UABA, 24 patients BABA, and 31 patients OA. Clinicopathologic data, surgical outcome, stimulated Tg and RAIU ratio on the first postoperative RAI ablation scan were compared among 3 groups. Results Patients in the endoscopic surgery groups (UABA, BABA) were younger than those in the OA groups. Invasiveness such as operation time, postoperative pain, and drain amount in UABA was less than that in BABA and severer than that in OA. Other variables regarding clinicopathologic and surgical data were not significantly different. Stimulated Tg and RAIU ratio did not show significant differences among 3 groups (p=0.659 and p=0.664). Conclusion The completeness of UABA was comparable with that of BABA and OA. The UABA may be a safe option for patients who need endoscopic thyroidectomy for papillary thyroid carcinoma.

• Advances in pediatric surgery
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• v.9 no.2
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• pp.89-93
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• 2003

A lipomatous lesion of the cord is an accidentally encountered structure during the operative repair of inguinal hernia. This lesion has been reported as a lipoma of the cord in adults. However, there is only a limited number of reports in the pediatric age group. To evaluate the prevalence of this lesion in children and in order to review the surgical signiticancies, 600 hernia operations in 411 children during a period of 4 years from January, 2000 to December, 2003 in the Division of Pediatric Surgery, Department of Surgery, the Catholic University of Korea, were included in this study. There was a total of 31 (5.2 %) lipomatous lesions in 25 (6.1 %) cases; 3 cases in infants, 17 between 1 to 4 years, and 5 above 5 years of age. Male was more prevalent (male to female ratio 14:11). The laterality of clinical hernia with the lesions was 10 in the right, 13 in the left and 2 in both sides. The patients with ipsilateral lesions to the hernia were 14, contralateral in 5 and bilateral in 6 cases. Excluding 1 case of bilateral lesions in bilateral hernia, 10 lesions were contralateral to the clinical hernias. In 1 case, lipomatous lesion was the sole finding with nonsignificant patent processus vaginalis. Every lesion was suture ligated and resected with gentle traction of the dissected hernia sac. It has not been clearly defined whether the lesion is a stopper or a provocator of the hernia development. However, removal is highly recommended to make a differential diagnosis from the recurrent inguinal hernia in future. The term "lipomatous lesion" seems to be pathologically accurate and must be differentiate from the true lipomas.

• Journal of Chest Surgery
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• v.21 no.2
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• pp.299-306
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• 1988

We have reviewed 330 cases of spontaneous pneumothorax from Jan. 1980 to Jul. 1987 at the department of Thoracic and Cardiovascular Surgery, College of Medicine, Korea University. The ratio of male to female was 8.4:1, predominant in male. The incidence according to the age group was highest as 32% in the adolescence between 21 and 30 years old. The site of pneumothorax was right in 48%, left in 45% and bilateral in 7%. The initial symptoms were frequently dyspnea in 85%, chest pain in 63%. The etiologic factors were as follows; bleb origin in 31%, tuberculous origin in 30%, COPD in 3.3%, lung cancer in 1.5%, unknown in 29%. There was no significant difference in seasonal incidence irrespective of tuberculous or sex. The employed managements were as follows; bed rest with oxygen inhalation in 4 cases, closed thoracostomy in 326 cases, open thoracotomy in 122 cases, median sternotomy in 23 cases. The operative procedures at thoracotomy were as follows; simple pleurodesis in 5 cases, bleb excision or wedge resection in 113 cases, segmentectomy or lobectomy in 17 cases, decortication in 42 cases. Recurrence rate of each treatment was as follow; 50% in conservative treatment, 19% in closed thoracostomy, 2% in open thoracotomy, 4% in median sternotomy. Therefore overall recurrence rate was 12%. Open thoracotomy was the most effective procedure in recurrent pneumothorax, previous contralateral pneumothorax, bilateral simultaneous pneumothorax, visible bleb or bullae on the chest x-ray and persistent air leakage. 23 cases of unilateral spontaneous pneumothorax was examined whether or not underlying pathology of pneumothorax at opposite lung. 18 cases[78%] were positive findings. Therefore, bilateral thoracotomy by median sternotomy was a good operative method preventing contralateral pneumothorax.

• Korean Journal of Ophthalmology
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• v.32 no.6
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• pp.488-496
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• 2018

Purpose: This study aimed to analyze the factors influencing visual field recovery after transsphenoidal approach-tumor resection (TSA-TR) in pituitary adenoma patients with visual field defects (VFDs). Methods: We retrospectively evaluated 102 eyes of 102 patients with VFDs induced by pituitary adenomas who underwent TSA-TR between January 2010 and December 2015. All patients had been observed for more than one year. The severity of the VFD in each patient was evaluated using the mean deviation (MD) and pattern standard deviation in the most-affected eye. Clinical and demographic data such as preoperative visual acuity and visual field, age, sex, tumor volume, neurological symptoms at diagnosis, duration of symptoms, patterns of the preoperative VFD, and preoperative central VFD were investigated and analyzed for association with recovery of the visual field. Results: Recovery from VFDs occurred in 71 (69.6%) eyes after a mean period of $18.36{\pm}5.21$ months. The recovery group was younger (p = 0.003), had higher preoperative MD values (p = 0.016), and had better preoperative visual acuity (p = 0.03), compared with the non-recovery group. Preoperative central VFD (p = 0.006) and preoperative bilateral VFD (p = 0.016) were significantly less frequent in the recovery group. Multivariate logistic regression revealed that age at diagnosis (odds ratio [OR], 0.962; p = 0.022), preoperative MD (OR, 1.069; p = 0.046), preoperative central VFD (OR, 0.212; p = 0.039), and preoperative bilateral VFD (OR, 0.212; p = 0.035) were associated with visual field recovery after TSA-TR. Conclusions: Younger age, higher preoperative MD, and the preoperative abscence of central VFD or bilateral VFD were favorable factors influencing visual field recovery after TSA-TR in patients with pituitary adenomas. An understanding of the associated clinical factors may help predict visual outcomes after TSA-TR in pituitary adenoma patients with VFDs.

• Journal of Chest Surgery
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• v.24 no.8
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• pp.757-764
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• 1991

We have observed 360 cases of spontaneous pneumothorax from January 1980 to May 1991 at the department of Thoracic and Cardiovascular Surgery, Chosun University Hospital. Males occupied 266 cases[73.9%] and females 94 cases[26.1%], and its ratio was 2.8: l. The age of patients ranged from neonate[5 days] to 84 years old. The site of pneumothorax was right in 50.3%, left in 43.3% and bilateral in 6.4%a. The clinical symptoms were frequently dyspnea, chest pain and coughing. The associated pulmonary lesions were shown pulmonary tuberculosis in 199 cases[55.3%], bullae in 54, pulmonary emphysema in 31, COPD in 17, pneumonia in 6, lung cancer in 5, paragonimiasis in 5, catamenial pneumothorax in 3 and unknown underlying pathology in 39 cases. The results of surgical management of spontaneous pneumothorax are followings: 288 out of 360 cases[80.0%] were cured by closed thoracotomy, 53 cases[14.8%] were cured by open thoracotomy. Open thoracotomy was the most effective procedure in persistent air leakage, recurrent pneumothorax, visible bleb or bullae on the chest X-ray, associated lesion, bilateral simultaneous pneumothorax, parenchymal incomplete lung expansion and bleeding after closed thoracotomy. The incidence of complication was developed in 10. ado and recurrent rate was seen in 10.6%. There was no operative death.

• Asia-Pacific Journal of Business
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• v.2 no.1
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• pp.49-73
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• 2011

With the market evaluation of economic globalization exchanges between different cultures, cultural trade has been developing at an accelerated speed, and also playing an important role in East Asian intra-regional trade. In this research the author used gravity trade model to explain the causal relationship between dependent variable trade flows and several independent variables applying with five categories cultural goods which classified in HS codes. Firstly for cultural heritage trade flow, the results indicated that economic masses of bilateral countries have no significant influences on it; GDP per capita of host country and adjacency factor with partner country have significant negative influences on it; Internet coverage ratio has improved cultural heritages exchanges in East Asian regions. Secondly for printed matter cultural goods trade flow, the distance factor has significant negative influence but common language has significant positive influence on it. Thirdly for recorded media cultural goods, only economic masses and GDP per capita of bilateral countries can improved their trade flows. Fourthly for visual arts cultural products trade flows, almost all variables we tested have significant influences on it. Fifthly for cinema photography cultural goods trade flow, the influenced factor are same with cultural heritage products except they have strong positive interaction relationship with economic masses and common language. At last, the paper figured out some important and potential sectors for cultural goods trade in East Asia and gave some suggestions to government and cultural goods product enterprises.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.386-386
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• 2012

We studied a bilateral switching device for spin transfer torque (STT-MRAM) based on 3D device simulation. Metal/P/N+or Metal/N/P+ junction device with $30{\times}30nm2$ area which is composed of one side schottky junction at Metal/P/N+ and Metal/N/P+ provides sufficient bidirectional current flow to write data by a drain induced barrier lowering (DIBL). In this work, Junction device confirmed that write current is more than 30 uA at 2 V, It is also has high on-off ratio over 105 under read operation. Junction device has good process feasibility because metal material of junction device could have been replaced by bottom layer of MTJ. Therefore, additional process to fabricate two outer terminals is not need. so, it provides simple fabrication procedures. it is expected that Metal/P/N+ or Metal/N/P+ structure with one side schottky junction will be a promising switch device for beyond 30 nm STT-MRAM.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.385-385
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• 2012

A two terminal N+/P/N+ junction device to replace the conventional selective transistor was studied as a bilateral switching device for spin transfer torque (STT) MRAM based on 3D device simulation. An N+/P/N+ junction structure with $30{\times}30nm$ area requires bi-directional current flow enough to write a data by a drain induced barrier lowering (DIBL) under a reverse bias at N+/P (or P/N+ junction), and high current on/off ratio of 106. The SiGe materials are widely used in hetero-junction bipolar transistors, bipolar compensation metal-oxide semiconductors (BiCMOS) since the band gap of SiGe materials can be controlled by changing the fraction and the strain epilayers, and the drift mobility is increased with the increasing Ge content. In this work, N+/P/N+ SiGe material based junction provides that drive current is increased from 40 to $130{\mu}A$ by increased Ge content from 10~80%. When Ge content is about 20%, the drive current density of SiGe device substantially increased to 2~3 times better than Si-based junction device in case of 28 nm P length, which is sufficient current to operation of STT-MRAM.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.1
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• pp.446-467
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• 2012

In this paper, the analysis and design of a motion simulator (based on the approach taken by interactive virtual reality (VR) entertainment systems) is conducted. The main components of the system include a bilateral control interface, simulation and a motion simulator control scheme. The space entertainment system uses a virtual environment that enables operators to feel the actual feedback sensing and distorted motion from the virtual environment, just as they would in the real environment. The space entertainment system integrates the dynamics of the motion simulator and the virtual environment and the operator maneuvers a steering wheel to interact with the system. The multiple bilateral control schemes employ a dynamical controller, which is designed by considering the velocity and acceleration that the operator imposes on the joystick, the environmental changes imposed on the motion simulator. In addition, we develop a calculated method to evaluate the Ratio of the simulation results. It is shown that the proposed control scheme can improve the performance of the visual entertainment system. Experiments are conducted on the virtual reality entertainment system to validate the theoretical developments.