• 전자공학회논문지
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• 제53권6호
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• pp.122-129
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• 2016

컴퓨터 비전(Computer vision) 분야에서 물체인식을 위한 많은 알고리즘이 연구되고 있다. 그중 특징점(feature) 기반의 SURF(Speeded Up Robust Features) 알고리즘은 다른 알고리즘에 비해 속도와 정확도 면에서 우수하다. 하지만 SURF 알고리즘은 대응점 검출 시 대응점 오정합으로 물체인식에 실패하는 단점이 있다. 본 논문은 물체 인식률을 향상하기 위하여 SURF와 RANSAC(Random Sample Consensus) 알고리즘을 기반으로 물체인식 시스템을 구현하고, 패턴인식 필터링을 제안하였다. 또한, 실험을 통하여 물체 인식률 향상 결과를 제시하였다.

• 한국정보전자통신기술학회논문지
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• 제9권1호
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• pp.38-44
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• 2016

본 논문에서는 움직임 벡터를 이용한 낙상 감지 시스템에 관해 기술한다. 두드러진 움직임을 위한 가중치 차영상 기법, 움직임 벡터를 이용하여 인간이라고 판단되는 블랍을 검출하고, 추출된 움직임 벡터를 이용하여 낙상 여부를 판단한다. 기존의 영상 기반 낙상 감지 시스템의 경우 특정 방향으로 낙상이 발생하는 경우에만 낙상 감지에 성공하였지만 제안 시스템의 경우 다양한 각도에서 낙상이 발생하여도 상황 판단이 가능하다는 장점이 있다. 실험을 위해서 150개의 상황을 연출하였으며, 약 85% ~ 97.1% 낙상 상황 판단 성공률을 보였다.

• Journal of Information Technology Applications and Management
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• 제17권4호
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• pp.127-156
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• 2010

Most companies in the IT service industry have suffered from low profitability although this industry is highly value added, which may result in losing the competitiveness of the industry. The purpose of this study is to identify the influencing factors on the profit improvement rate of IT service projects and suggest how to improve the profit improvement rate, thus recovering the competitiveness of the IT service industry. The 273 IT service projects conducted by an IT service company in Korea during the past three years were analyzed and the project managers who performed these projects responded to the questionnaire developed in this study. The result from the analysis of data collected shows that the influencing factors on the profit improvement rate of IT service projects include scheduling, experience in similar projects, the leadership of project leaders, the level of team skills, relationship with clients, and clients support.

• 한국멀티미디어학회논문지
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• 제9권3호
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• pp.279-286
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• 2006

주파수 분포벡터를 이용한 분류방법을 국악기 분류 및 인식에 적용하였으며 분류에 사용되는 주파수 분포 벡터 중에서 리듬성분을 수치화한 평균피크값을 제안하였다. 대부분의 주파수 처리함수들은 주파수값의 평균, 통계적특성에 기반을 두고 있으며 국악기자동분류를 위해 신호의 평균, 분산, 영교차율, 균형주파수, 평균 피크값을 이용하여 실험하였다. 국악의 장르 구분을 위한 선행 연구로서 음악신호를 함수처리하고 k-최근접이웃 분류알고리즘을 적용하여 분류하였다. 기존의 주파수 분포벡터를 이용하여 발표되었던 서양음악의 분류 성공률 87%보다 향상된 94.44%의 성공률을 나타냈다.

• Journal of Periodontal and Implant Science
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• 제44권1호
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• pp.2-7
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• 2014

Implants have been widely used in restorative treatment for patients who have undergone head and neck cancer surgery. With the development of combination treatment of head and neck cancer, radiotherapy has been a common means of therapy. However, it could induce various changes in hard and soft tissues and reduce the success and survival rate of the implants. Some research, using either animal models or clinical studies, have shown that certain strategies could be used for improving the survival rate of implants. In this review, we discussed the changes in both hard and soft tissues, which may reduce the survival rate of the implants, and the proposed methods for improving the survival rate of patients after radiotherapy.

• 정보처리학회논문지:컴퓨터 및 통신 시스템
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• 제2권3호
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• pp.125-132
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• 2013

본 논문은 DDoS 공격과 유사한 트래픽을 생성하고 ISP를 포함한 네트워크를 통해 실제 운용 중인 웹서버에 전송하여 결과를 분석하였다. 결과 분석을 위해서 대응 장비의 관리 주체에 따라 DDoS 공격의 대응 방법을 ISP(Top), 네트워크(Middle), 시스템(Bottom) 레벨 대응으로 분류하였으며 전송 트래픽을 특징에 따라 4종으로 분류하였다. 실험 결과는 48개 홈페이지의 대응 레벨별 평균 공격 성공률과 공격 분류별 평균 공격 성공률을 기술 및 분석하였으며 2개의 예외 상황에 대해서 기술하였다. 5장에서는 실험 결과를 기반으로 피해완화방안을 제시하였다.

• Journal of Korean Biological Nursing Science
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• 제22권3호
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• pp.176-183
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• 2020

Purpose: : The purpose of this study was to evaluate the intrauterine insemination (IUI) success rate and to define the variables for predicting success. Methods: The secondary data analysis was used with data collected from infertile females who underwent IUI in Fertility and IVF (In Vitro Fertilization) clinics, who benefited from the 'National Medical-aid Program for ART (assisted reproductive technology) in 2016', in which the data of 34,920 IUI cases were retrospectively reviewed. The primary outcome measure was the clinical pregnancy rate in elderly and young infertile females. Data were analyzed by descriptive statistics, χ2 test and logistic regression. Results: The pregnancy rate was 12.1% (2,095 cases) in elderly infertile females and 15.6% in young infertile females (2,758 cases) (χ2 = 87.90, p< .001). Using the logistic regression analysis, clinical pregnancy was positively associated with the ovulatory factor (OR= 1.48, p< .001) and male factor (OR= 1.19, p< .05) in elderly infertile females. It was positively associated with the ovulatory factor (OR= 1.30, p= .001) and the peritoneal cavity factor (OR= 0.58, p< .05) in young infertile females. Conclusion: Our results indicate that the pregnancy rate in young infertile females was higher than that in old infertile females, and the IUI is the effective option in pregnancies in all ages with infertility due to the ovulatory factor. Additionally, further studies are necessary to fully describe pregnancy experiences for all the infertile females.

• Journal of Yeungnam Medical Science
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• 제20권2호
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• pp.169-176
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• 2003

Background: Although dental implantation has become widespread and acceptable treatment for dental prosthodontics, maxillary posterior jaw region is often complicated by the pneumatization of the maxillary sinus and physiological resorption of the alveolar bone. When this occurs, the residual bone between the floor of the sinus and the crestal ridge is inadequate for the placement of implants. The sinus elevation procedure provides a way to increase the amount of available bone and to allow the placement of longer implants. Materials & methods: We studied 11 patients requiring the implant placements and the maxillary sinus elevation simultaneously from 1996 to 2003 in our clinic. Nine patients were males and two patients were females, aged from 39 to 72(mean=51.6). Four patients had medical compromised states; angina pectoris, diabetes, hypertension, hepatitis. Patients didn't show any pathologic findings clinically or radiographically. We studied the success and survival rate of implants, factors increasing the osseointegrating capacity of implants. Results: The success rate of osseointegration of implants was 93%. At least 6 months after loading on implants, the survival rate of implants was 78.5%. Autogenous bone graft and adequate residual bone height(>6mm) increased survival rate of implants. Conclusion: Successful implant placement with maxillary sinus elevation mainly depends on sufficient residual bone height, healthy maxillary sinus, autogenous bone graft.

• 한국정보과학회논문지:데이타베이스
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• 제32권2호
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• pp.151-160
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• 2005

웹 문서들은 빈번하게 생성, 소멸, 변경을 반복하고 있으며, 웹 데이타베이스는 최신의 웹 상태를 반영하여야 한다. 웹 데이타베이스의 효과적인 갱신 전략 수립을 위하여 실제 웹의 변화 성향을 파악하는 일은 매우 중요하다. 웰의 변화를 관찰한 연구들이 다양하게 발표되고 있으나 기존의 연구들은 웹 문서의 내용 변경에 주된 초점이 맞추어 있고 웹 문서의 생성과 소멸에 대한 결과가 부족하였다. 본 논문에서는 쇌 문서의 변화를 표현할 수 있는 척도로서 URL의 '다운로드 성공률', '변경률', '나이 변이 계수'를 소개하고, 한국의 유명 사이트 집합과 임의(random) 사이트 집합에서 발견된 300만 개의 URL들이 2 일 주기로 100일 동안 관찰한다. 본 논문에서는 '다운로드 성공률'과 '변경률'의 분포를 통해 웰 문서의 다운로드 성공과 변경이 과거 기록과 밀접한 연관이 있음을 발견하였으며, 과거 기록을 이용하여 향후 웹 문서의 다운로드 성공과 변경을 예측할 수 있는 모델을 제안한다. 또한, '나이 변이 계수'를 통해 웹 문서들이 얼마나 비주기적으로 변경되는가를 보고한다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제38권
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• pp.35.1-35.5
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• 2016

Background: Mucous retention cyst refers to a cyst made by expansion due to the blockage of the salivary gland near the maxillary sinus, and it is surrounded by epithelial cells. Most of them are small; therefore, they cannot be found well and are frequently with antral polyp. The aim of this study was to evaluate the clinical prognosis of sinus bone graft in patients with mucous retention cyst. Methods: This study was performed retrospectively on 23 patients who had sinus bone graft. Group 1 was 8 patients (10 sinuses) who had a mucous retention cyst, and group 2 was 15 patients (17 sinuses) who had no pathologic history about the maxillary sinus. For these patients, sinus bone graft was performed using the lateral approach technique. The total 51 implants were placed 6.22 weeks on the average after sinus bone graft. Sinus membrane perforation during operation, postoperative complications, marginal bone loss after restorative function, implant success rate, and survival rate were analyzed. Results: There was no complication in group 1, and there were three complications in group 2. In group 2, two cases of implants failed. The types of postoperative complications consisted of two minor infections and one wound dehiscence. Two implants of total 51 implants were removed, and the survival rate of implants was 96.08 % (group 1 100 %, group 2 93.5 %). The total success rate of implants was 92.2 % (group 1 95 %, group 2 90.3 %). Conclusions: The clinical prognosis was not affected by the presence of mucous retention cyst.