• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.5C
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• pp.527-539
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• 2009

In this paper, we propose an asynchonous ICI (Inter-Cell Interference) mitigation techniques for 3GPP LTE MIMO-OFDMA down-link receiver. An increasing in symbol timing misalignments may occur relative to sychronous network as the result of BS (Base Station) timing differences. Such symbol synchronization errors that exceed the guard interval or the cyclic prefix duration may result in MAI (Multiple Access Interference) for other carriers. In particular, at the cell boundary, this MAI becomes a critical factor, leading to degraded channel throughput and severe asynchronous ICI. Hence, many researchers have investigated the interference mitigation method in the presence of asynchronous ICI and it appears that the knowledge of the SCM (Spatial Covariance Matrix) of the asynchronous ICI plus background noise is an important issue. Generally, it is assumed that the SCM estimated by using training symbols. However, it is difficult to measure the interference statistics for a long time and training symbol is also not appropriate for MIMO-OFDMA system such as LTE. Therefore, a noise reduction method is required to improve the estimation accuracy. Although the conventional time-domain low-pass type weighting method can be effective for noise reduction, it causes significant estimation error due to the spectral leakage in practical OFDM system. Therefore, we propose a time-domain sinc type weighing method which can not only reduce the noise effectively minimizing estimation error caused by the spectral leakage but also implement frequency-domain moving average filter easily. By using computer simulation, we show that the proposed method can provide up to 3dB SIR gain compared with the conventional method.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.18
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• pp.8141-8143
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• 2016

Background: to evaluate the outcome of stapled colo-anal anastomoses after extended low anterior resection for distal rectal carcinoma. Materials and Methods: A retrospective study of fifty patients who underwent coloanal anastomoses after extended low anterior resection was conducted at Imam Hospital from September 2007 up to July 2012. Results: The distance of the tumor from anal verge was 3 to 8 cm. Anastomotic leakage developed in 6% of patients and defecation problems in 16%. One-year local recurrence was 6% while three-year local recurrence was 4%. One-year systemic recurrence was seen in 22% while three-year systemic recurrence was seen in 20%. Conclusions: Colo-anal anastomoses after extended low anterior resection for distal rectal carcinoma can be conducted safely.

• Journal of Multimedia Information System
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• v.9 no.2
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• pp.103-112
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• 2022

Background: A presentation attack places the printed image or displayed video at the front of the sensor to deceive the biometric recognition system. Usually, presentation attackers steal a genuine user's biometric image and use it for presentation attack. In recent years, reconstruction attack and adversarial attack can generate high-quality fake images, and have high attack success rates. However, their attack rates degrade remarkably after image shooting. Methods: In order to comprehensively analyze the threat of presentation attack to palmprint recognition system, this paper makes six palmprint presentation attack datasets. The datasets were tested on texture coding-based recognition methods and deep learning-based recognition methods. Results and conclusion: The experimental results show that the presentation attack caused by the leakage of the original image has a high success rate and a great threat; while the success rates of reconstruction attack and adversarial attack decrease significantly.

• Journal of Chest Surgery
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• v.51 no.1
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• pp.1-7
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• 2018

Background: Sutureless aortic valve replacement (SU-AVR) has been developed as an alternative surgical treatment for patients with symptomatic severe aortic stenosis (AS). The aim of this study was to evaluate the clinical outcomes of SU-AVR through an assessment of hemodynamic performance and safety. Methods: From December 2014 to June 2016, a total of 12 consecutive patients with severe AS underwent SU-AVR. The endpoints were overall survival and valve-related complications (paravalvular leakage, valve thrombosis, migration, endocarditis, and permanent pacemaker implantation). The mean follow-up duration was $18.1{\pm}8.6months$. Results: The mean age of the patients was $77.1{\pm}5.8years$ and their mean Society of Thoracic Surgeons score was $9.2{\pm}17.7$. The mean cardiopulmonary bypass and aortic cross-clamp times were $94.5{\pm}37.3$ minutes and $54.9{\pm}12.5minutes$, respectively. Follow-up echocardiography showed good prosthesis function with low transvalvular pressure gradients (mean, $13.9{\pm}8.6mm\;Hg$ and peak, $27.2{\pm}15.0mm\;Hg$) at a mean of $9.9{\pm}4.2months$. No cases of primary paravalvular leakage, valve thrombosis, migration, or endocarditis were reported. A new permanent pacemaker was implanted in 1 patient (8.3%). The 1-year overall survival rate was $83.3%{\pm}10.8%$. Conclusion: Our initial experience with SU-AVR demonstrated excellent early clinical outcomes with good hemodynamic results. However, there was a high incidence of permanent pacemaker implantation compared to the rate for conventional AVR, which is a problem that should be solved.

• Archives of Plastic Surgery
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• v.40 no.6
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• pp.735-741
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• 2013

Background The prosthetic dura is an essential element in the protection of the cranial parenchyma and prevention of cerebrospinal fluid leakage. Although prosthetic dura are widely used in neurosurgery, they occasionally provoke infection, which can be a major concern after neurosurgical treatment. However, removal of the prosthetic dura carries a risk of brain parenchyma injury and cerebrospinal fluid leakage. The salvage of infected prosthetic dural material has not been adequately addressed in the literature. In this study, we demonstrate the value of the combination of a meticulous surgical debridement of necrotic tissue and simultaneous muscle free flap for intractable postoperative epidural abscess without removal of the infected prosthetic dura. Methods Between 2010 and 2012, we reviewed the data of 11 patients with persistent infection on the prosthetic dura. The epidural infections each occurred after a neurosurgical procedure, and there was soft tissue necrosis with the disclosure of the underlying prosthetic dura and dead bone around the scalp wound. To salvage the infected prosthetic dura, meticulous debridement and a muscle free flap were performed. Results All 11 patients experienced complete recovery from the complicated wound problem without the need for further surgical intervention. No signs of prosthetic dural infection were observed during the mean follow-up period of 11 months. Conclusions The combination of a meticulous surgical debridement and coverage with a muscle free flap is an effective treatment for salvage of infected prosthetic dura.

• Journal of Chest Surgery
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• v.46 no.5
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• pp.346-352
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• 2013

Background: Transcatheter aortic valve implantation (TAVI) has been an alternative to conventional aortic valve replacement (AVR) in old and high risk patients. The goal of this study is to compare the early outcomes of conventional AVR vs. TAVI in high risk severe AS patients. Methods: From January 2008 to July 2012, 44 high risk severe aortic stenosis patients underwent conventional AVR, and 15 patients underwent TAVI. We compared echocardiographic data, periprocedural complication, and survival. The mean follow-up duration was $14.5{\pm}10$ months (AVR), and $6.8{\pm}3.5$ months (TAVI), respectively. Results: AVR group was younger ($78.2{\pm}2.4$ years vs. $82.2{\pm}3.0$ years, p<0.001) and had lower operative risk (Euroscore: $9.4{\pm}2.7$ vs. $11.0{\pm}2.0$, p=0.044) than TAVI group. There was no significant difference in early mortality (11.4% vs. 13.3%, p=0.839), and 1 year survival ($87.4%{\pm}5.3%$ vs. $83.1%{\pm}1.1%$, p=0.805). There was no significant difference in postoperative functional class. There was no significant difference in periprocedural complication except vascular complication (0% [AVR] vs. 13.3% [TAVI], p=0.014). TAVI group had more moderate and severe paravalvular leakage. Conclusion: In this study, both groups had similar periprocedural morbidity, and mortality. However, TAVI group had more greater than moderate paravalvular leakage, which can influence long-term outcome. Since more patients are treated with TAVI even in moderate risk, careful selection of the patients and appropriate guideline need to be established.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.5
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• pp.2778-2791
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• 2017

In the age of big data, distributed data providers need to ensure the privacy, while data analysts need to mine the value of data. Therefore, how to find the privacy-utility tradeoff has become a research hotspot. Besides, the adversary may have the background knowledge of the data source. Therefore, it is significant to solve the privacy-utility tradeoff problem in the distributed environment with side information. This paper proposes a distributed privacy-utility tradeoff method using distributed lossy source coding with side information, and quantitatively gives the privacy-utility tradeoff region and Rate-Distortion-Leakage region. Four results are shown in the simulation analysis. The first result is that both the source rate and the privacy leakage decrease with the increase of source distortion. The second result is that the finer relevance between the public data and private data of source, the finer perturbation of source needed to get the same privacy protection. The third result is that the greater the variance of the data source, the slighter distortion is chosen to ensure more data utility. The fourth result is that under the same privacy restriction, the slighter the variance of the side information, the less distortion of data source is chosen to ensure more data utility. Finally, the provided method is compared with current ones from five aspects to show the advantage of our method.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.15 no.1
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• pp.343-355
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• 2002

Background : Although Samsoeum has been used frequently on allergic rhinitis, but there isn't any experimental research for that. Objective : This study was performed to investigate the anti-allergic effects of Samsoeum and Samsoeumgamibang. Materials and Methods : Katayama's method was used to observe the vascular permeability response induced by serotonin and histamine. Muller's method was used to observe the contact dermatitis response induced by picryl chloride. Miller's method was used to observe the delayed type hypersensitivity response to SRC. Results : 1. In the vascular permeability response to intradermal injection of serotonin, 2,600mg/kg, p.o. group of Samsoeum(蔘蘇飮), 1,300 and 2,600mg/kg, p.o. group of Samsoeumgamibang(蔘蘇飮加味方) showed significant inhibitory effects on the leakage of Evan's blue solution. 2. In the vascular permeability response to intradermal injection of histamine, 1,300 and 2,600mg/kg, p.o. group of Samsoeum, also 1,300 and 2,600mg/kg, p.o. group Samsoeumgamibang showed significant inhibitory effects on the leakage of Evan's blue solution. 3. In the contact dermatitis response induced by picryl chloride, 1,300 and 2,600mg/kg, p.o. group of Samsoeum, 1,300 and 2,600mg/kg, p.o. group of Samsoeumgamibang showed significant inhibitory effects on ear swelling formation. 4. In the delayed type hypersensitivity response to SRC. 2,600mg/kg, p.o. group of Samsoeum and 2,600mg/kg, p.o. group of Samsoeumgamibang showed significant inhibitory effects on foot swelling. Conclusion : This study shows that Samsoeum and Samsoeumgamibang may have anti-allergic effects. So Samsoeum and Samsoeurngamibang can be helpful to treat allergic rhinitis.

• Korean Journal of Bronchoesophagology
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• v.6 no.1
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• pp.62-71
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• 2000

Background: For the purpose of reducing operating time and rate of anastomotic leakage, we have performed esophagovisceral anastomosis with an EEA stapler using the largest size possible. If any difficulty in the approach of the EEA stapler was encountered one-layer interrupted hand-sewn anastomosis. Because the rate of postoperative benign anastomotic stricture was higher than expected, a retrospective study was done on all patients who underwent esophageal reconstruction. Material and Method: Over a period of 3 years from January 1996 to December 1998, we performed esophageal reconstructions on 30 patients. Patients were divided into two groups ; EEA stapler group(Group Ⅰ) comprised of 21 patients and hand-sewn group(Group Ⅱ) comprised of 9 patients.Result:The hospital mortality was 6.67 %(2/30) and the anastomotic leakage rate was 3.33 %(1/30). Among the discharged patients, the rate of recurrent anastomotic tumor was 3.57 %(1/28) and the rate of benign anastomotic stricture stricture rate was 35 %(7/20) in Group Ⅰ and 12.5 %(1/8) in Group Ⅱ, which was not significant. Conclusion: Although nontumor benign stricture was significantly higher in Group Ⅱ than in Group Ⅰ(p=0.0492), the incidence of anastomotic complications did not differ between the two groups. The one-layer interrupted hand-sewn esophagovisceral anastomosis by maintaining a wide lumen and close approximation of mucosa to mucosal layers with evenly spaced sutures could be one of the preferred surgical method to reduce benign anastomotic strictures.

• Journal of Yeungnam Medical Science
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• v.38 no.2
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• pp.142-147
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• 2021

Background: This study was performed to investigate the association between cystographic anastomotic urinary leakage (UL) after retropubic radical prostatectomy (RRP) and early urinary incontinence (UI). Methods: The medical records of 53 patients who had undergone cystography after RRP at our institution between January 2015 and December 2018 were retrospectively analyzed. Cystography was performed 7 to 10 days after surgery. The duration of catheterization depended on the degree of UL, which was classified as mild, moderate, or severe. The study subjects were divided into the non-UL group and the UL group. Continence was defined as the use of no pads. The prostate was dissected in an antegrade fashion, and urethrovesical anastomosis was performed with a continuous suture. Results: Incontinence rates at 1 and 3 months postoperatively were significantly higher in the UL group than the non-UL group (83.3% vs. 52.2%, p=0.014 and 76.7% vs. 47.8%, p=0.030, respectively); however, those at 6 and 12 months were not significantly different (23.3% vs. 17.4%, p=0.597 and 4.3% vs. 10.0%, p=0.440, respectively). The severity of UL was not found to influence the duration of incontinence. The presence of cystographic anastomotic UL was found to be predictive of UI during the first 3 postoperative months (odds ratio, 3.3; p=0.045). Conclusion: The presence of anastomotic UL on cystography was associated with higher rates of UI in the early postoperative periods. However, incontinence rates in patients with or without anastomotic UL immediately after RRP equalized at 6 months and the severity of UL did not affect the duration of postoperative UI.