• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제34권5호
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• pp.555-561
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• 2008

Purpose: The goal of this study was to develop a technique for creating a computerized composite maxillofacial-dental model, based on point-based surface best fit algorithm and to test its accuracy. The computerized composite maxillofacial-dental model was made by the three dimensional combination of a 3-dimensional (3D) computed tomography (CT) bone model with digital dental model. Materials and Methods: This integration procedure mainly consists of following steps : 1) a reconstruction of a virtual skull and digital dental model from CT and laser scanned dental model ; 2) an incorporation of dental model into virtual maxillofacial-dental model by point-based surface best fit algorithm; 3) an assessment of the accuracy of incorporation. To test this system, CTs and dental models from 3 volunteers with cranio-maxillofacial deformities were obtained. And the registration accuracy was determined by the root mean squared distance between the corresponding reference points in a set of 2 images. Results and Conclusions: Fusion error for the maxillofacial 3D CT model with the digital dental model ranged between 0.1 and 0.3 mm with mean of 0.2 mm. The range of errors were similar to those reported elsewhere with the fiducial markers. So this study confirmed the feasibility and accuracy of combining digital dental model and 3D CT maxillofacial model. And this technique seemed to be easier for us that its clinical applicability can good in the field of digital cranio-maxillofacial surgery.

• Nuclear Engineering and Technology
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• 제44권1호
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• pp.61-70
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• 2012

In this study, a simple post-reconstruction dual-energy computed tomography (CT) method is proposed. A dual-energy CT algorithm for monochromatic x-rays was adopted and applied to the dual-energy CT of polychromatic x-rays by assigning a representative mono-energy. The accuracy of algorithm implementation was tested with mathematical phantoms. To test the sensitivity of this algorithm to the inaccuracy of representative energy value in energy values, a simulation study was performed with mathematical phantom. To represent a polychromatic x-ray energy spectrum with a single-energy, mean energy and equivalent energy were used, and the results were compared. The feasibility of the proposed method was experimentally tested with two different micro-CTs and a test phantom made of polymethyl methacrylate (PMMA), water, and graphite. The dual-energy calculations were carried out with CT images of all possible energy pairs among 40, 50, 60, 70, and 80 kVp. The effective atomic number and the electron density values obtained from the proposed method were compared with theoretical values. The results showed that, except the errors in the effective atomic number of graphite, most of the errors were less than 10 % for both CT scanners, and for the combination of 60 kVp and 70 kVp, errors less than 6.0 % could be achieved with a Polaris 90 CT. The proposed method shows simplicity of calibration, demonstrating its practicality and feasibility for use with a general polychromatic CT.

• 정보처리학회논문지:컴퓨터 및 통신 시스템
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• 제3권4호
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• pp.125-128
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• 2014

OpenGL ES(OpenGL for Embedded System) 2.0은 현재 스마트 폰과 태블릿 PC에서 가장 널리 사용되고 있는 3차원 그래픽스 API표준이다. 이를 이용하는 개발과정에서는 상대적으로 성능이 떨어지는 모바일 환경보다는 데스크 탑 환경이 선호된다. 따라서, OpenGL 라이브러리만 제공되는 데스크 탑 환경에서, 모바일 그래픽스 환경에서의 OpenGL ES 2.0 API를 그대로 에뮬레이션 할 필요가 있다. 본 논문은 PC 상에서 OpenGL ES 2.0 을 에뮬레이션하기 위해, 기술적 문제점들을 극복하는 방법들과 이에 따른 구현 결과를 제시한다. 구현된 OpenGL ES 2.0 에뮬레이션 라이브러리는 데스크 탑 PC 상에서 동작하고, 공식적인 검증 테스트(conformance test suite)의 96%이상을 통과하여, 구현의 정확성을 보였다. 또한, 상업적으로 제공되는 벤치마크 프로그램들에 대한 테스트에서 기존의 상업적 구현 사례와 동등한 수행 속도를 보였다.

• Restorative Dentistry and Endodontics
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• 제47권1호
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• pp.4.1-4.13
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• 2022

Objectives: This study evaluated the effects of different smear layer preparations on the dentin permeability and microtensile bond strength (µTBS) of 2 self-etching adhesives (Clearfil SE Bond [CSE] and Clearfil Tri-S Bond Universal [CTS]) under dynamic pulpal pressure. Materials and Methods: Human third molars were cut into crown segments. The dentin surfaces were prepared using 4 armamentaria: 600-grit SiC paper, coarse diamond burs, superfine diamond burs, and carbide burs. The pulp chamber of each crown segment was connected to a dynamic intra-pulpal pressure simulation apparatus, and the permeability test was done under a pressure of 15 cmH₂O. The relative permeability (%P) was evaluated on the smear layer-covered and bonded dentin surfaces. The teeth were bonded to either of the adhesives under pulpal pressure simulation, and cut into sticks after 24 hours water storage for the µTBS test. The resin-dentin interface and nanoleakage observations were performed using a scanning electron microscope. Statistical comparisons were done using analysis of variance and post hoc tests. Results: Only the method of surface preparation had a significant effect on permeability (p < 0.05). The smear layers created by the carbide and superfine diamond burs yielded the lowest permeability. CSE demonstrated a higher µTBS, with these values in the superfine diamond and carbide bur groups being the highest. Microscopic evaluation of the resin-dentin interface revealed nanoleakage in the coarse diamond bur and SiC paper groups for both adhesives. Conclusions: Superfine diamond and carbide burs can be recommended for dentin preparation with the use of 2-step CSE.

• 보건행정학회지
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• 제14권4호
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• pp.48-74
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• 2004

Considering the existence of asymmetric information between doctor and patient, the doctor's reimbursement method has been considered as a desirable policy device of improving efficiency of patient's use of medical care in terms of its affecting doctor's practice pattern by determining doctor's practice revenue. By using the Community Tracking Study (CTS) physician data set, which includes not only various information on doctors practice arrangements and sources of practice revenue, but also vignettes of various clinical presentations, this paper investigates doctor's reaction to the financial incentive under the control of patient's specific medical situation. Under the econometric model for exploring the effect of doctor's reimbursement method on his/her practice patterns; referring patients, recommend doctor-visit or medical tests, the Hausman's specification test was used for checking out the possibility of the doctor's reimbursement method being endogeneized explanatory variable. In the case where the endogeneity problem of doctor's reimbursement method exists, the 2SLS method was used for correcting that problem, and the multiple regression method was used in the case where the problem is found to be nonexistent. Based on the empirical results, this paper finds that doctors do appear to respond to financial incentive. The empirical results show that the doctor's reimbursement method statistically significantly affects doctor's practice pattern and are coincident with the theoretical result proposed by previous researches, This results suggest, as doctor's practice revenues are mainly determined by prospective method, such as capitation, doctors would more refer their patients to specialists, and hesitate in recommending doctor-visit or medical exam.

• Journal of Preventive Medicine and Public Health
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• 제29권3호
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• pp.507-519
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• 1996

The objectives of this study are to investigate the prevalence of occupation related carpal tunnel syndrome(CTS) among workers in a condom industry : to analyse the sensitivity and specificity of clinical signs or symptoms such as hand diagram, Tinel's sign and Phalen's sign in carpal tunnel syndrome : and to test vibration threshold test using audiometry as a technically easy and noninvasive method in the diagnosis of carpal tunnel syndrome in stead of nerve conduction velocity (NCV). The study group was divided into exposed group(39 cases) and non-exposed group(48 cases) based on whether or not excessive use of wrist movements exsist. 1. There are stastically significant differences in symptoms and signs of carpal tunnel syndrome such as hand diagram, Tinel's sign and Phalen's sign between exposed and non-exposed group(p<0.05). 2. Six cases(9 hands) were comfirmed as carpal tunnel syndrome by NCV. Five cases(7 hands) belonged to exposed group, 1 case(2 hands) to nonexposed group. As there are significant differences in prevalence of carpal tunnel syndrome between two groups(p<0.05), excessive use of wrist in occupation is a risk factor of carpal tunnel syndrome. 3. When we use NCV as a gold standard in the diagnosis of carpal tunnel syndrome, sensitivity and specificity of hand diagram, Tinel's sign and Phalen's sign is as followed; hand diagram , sensitivity 88.9%, specificity 84.2% Tinel's sign ; sensitivity 55.6%, specificity 72.8% Phalen's sign ; sensitivity 14.3%, specificity 88.4%. Among above clinical signs and symptoms, hand diagram is the best clinical screening test. 4. The differences of vibration threshold between median and ulnar nerve at the same time are useful in the diagnosis of carpal tunnel syndrome but the time change of vibration threshold of median nerve over time are not sensitive enough. It is concluded that vibration threshold between median and ulnar nerve at the same time can be used as a supplementary or alternative criterion to indicate that the nerve dysfunction is located in the carpal tunnel.

• 핵의학기술
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• 제15권1호
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• pp.90-93
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• 2011

Pixelated BSGI 감마카메라는 높은 분해능과 민감도를 특징으로 하며, 좁은 FOV로 인하여 검출기와 장기간의 거리를 최소화 할 수 있는 장점이 있다. 따라서, 국소 장기인 갑상선, 부갑상선, 담낭 등의 검사에 유용하다고 알려져 있다. 일반적으로 핵의학 검사에서 감마카메라를 사용하여 국소 장기를 영상화할 때 상의 크기를 확대하고, 우수한 분해능을 획득하고자 바늘구멍 조준기(Pinhole Collimator)를 사용한다. 이에 본 연구에서는 대표적인 국소장기인 갑상선 검사를 대상으로 바늘구멍 조준기로 획득한 영상 과 Pixilated BSGI 감마카메라로 획득한 영상을 비교하여 갑상선 검사 시 Pixilated Breast-Specific Gamma Imaging(BSGI) 감마카메라의 유용성을 평가 하였다. $^{99m}TcO_4^-$을 넣은 갑상선 팬텀을 이용 하였다. 바늘구멍 조준기를 장착한 INFINIA 감마카메라와 저 에너지 고 분해능용 평행다중구멍 조준기를 장착한 Pixelated BSGI 감마카메라에서 300 sec 또는 100 kcts로 설정 후 영상을 획득하였다. 모든 영상 획득은 현재 서울아산병원에서 실제 환자에게 적용하고 있는 갑상선 검사 절차와 동일한 방법으로 시행하였다. 그 결과 INFINIA 감마카메라와 Pixelated BSGI 감마카메라의 갑상선 팬텀 영상을 비교한 결과 Pixellated BSGI 감마카메라에서 갑상선 팬텀의 열소(hot spot)와 냉소(cold spot)의 구분을 더욱 명확하게 확인 할 수 있었다. 갑상선 검사시 Pixilated BSGI 감마카메라는 영상획득 시간을 단축시킬 수 있을 뿐만 아니라 더 나아가 투여하는 방사성의약품의 양을 줄임으로써 환자의 피폭을 경감 시킬 수 있다. 촬영시간의 단축은 환자의 호흡 및 움직임을 최소화하여 더 좋은 영상을 얻을 수 있다. 또한 Pixelated BSGI 감마카메라의 검출기는 작고 다양한 회전이 가능하므로 장기와 검출기 사이 거리를 최소화 할 수 있고, 장비자체의 이동도 가능하므로 환자의 이동이 불가 한 경우 매우 유용하다. 그러나 이러한 장점에도 불구하고 Pixelated (BSGI) 감마카메라는 방사성의약품의 집적이 매우 낮은 유방 촬영 전용으로 제작했기 때문에 2000 cts/s 이상에서는 불감시간 효과가 발생한다. 따라서 Pixelated BSGI 감마카메라를 핵의학 갑상선 검사에 적용할 경우 방사성의약품의 투여량의 조절과 영상획득 시간의 조정에 대한 연구가 더 필요할 것으로 사료된다.

• 대한통합의학회지
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• 제11권2호
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• pp.23-35
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• 2023

Purpose : Lung cancer induces a decrease in physical activity and a deterioration of respiratory ability. Exercise is an effective treatment to reduce side effects of anti-cancer treatments, also influence the survival and successful rehabilitation in lung cancer patients. However, there is insufficient evidence to show which period is the most effective to apply exercise for lung cancer patients. Therefore, this study was conducted to evaluate the efficacy of exercise-based interventions before and after surgery. Methods : Clinical trials (CTs) and randomized controlled trials (RCTs) reported in PubMed database were investigated. The trials investigated in this study were published for 10 years before August 20, 2022. The risk of bias was judged according to the Cochrane guideline. The materials included in this meta-analysis were 6-minute walk test (6MWT), pulmonary function, and quality of life (QOL). Results : 1 CT and 9 RCTs were selected in current study. In the meta-analysis, exercise increased 6MWT in preoperation (mean difference [MD] 29.49; 95 % confidence interval [CI] .99 to 57.99; p=.04; I²=0 %), 3 months postoperation (MD 54.97; 95 % CI 31.85 to 78.09; p<.001; I²=45 %) and 6 months postoperation (MD 85.59; 95 % CI 45.06 to 126.12; p<.001; I²=47 %). Exercise, also enhanced the lung function such as FEV₁/FVC (%) in postoperation (MD 7.64; 95 % CI 6.26 to 9.02; p<.001; I²=19 %). Additionally, exercise improved QOL, such as preoperative EORTC-QLQ-C30-LC13 in mental function (MD 3.21; 95 % CI .64 to 5.79; p=.01; I²=0 %) and postoperative SF-36 in mental component summary (MD 9.24; 95 % CI 4.94 to 13.54; p<.001; I²=0%). Conclusion : These results indicate that exercise-based intervention can elevate the ability to exercise and the mental componentof QOL within 3 months.

• 한국심리학회지 : 문화 및 사회문제
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• 제9권2호
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• pp.61-78
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• 2003

본 연구에서는 한국 대학생의 음주 행동과 데이트 폭력의 관계를 검증하였다. 연구 참여자는 이성과의 데이트 경험이 있는 440명의 대학생이었는데, 남학생이 184명이고 여학생이 256명이었다. 이들의 연령 분포는 17세에서 30세까지이었으며, 평균 연령은 20.08세(SD=1.89)였다. Straus의 갈등 책략척도(CTS), 알코올장애분류검사(AUDIT), Cooper의 음주동기 설문지(DMQ), 및 음주가족력목록(IFAU)을 참여자에게 주었다. 주요 통계분석은 2(성별) × 2(데이트 폭력 가해 경험) 이원변량분석 이었다. 분석 결과, 일주일에 한번 이상 술을 마시는 대학생이 그렇지 않은 대학생보다 데이트를 하면서 이성친구에게 폭력을 행할 가능성이 높았다. 여학생보다는 남학생들이 음주에 더 동기화가 되어 있었으며, 데이트 폭력 가해 경험이 있는 학생이 그렇지 않은 학생보다 대처동기를 가지고 술을 마시는 것으로 나타났다. 남학생은 여학생보다 문제음주, 즉 위험음주, 의존음주, 유해음주를 더 하고, 데이트 폭력 가해 경험이 있는 학생이 그렇지 않은 학생보다 문제음주를 더 하는 경향이 있었다. 또한, 데이트 폭력 가해 경험이 있는 학생이 그렇지 않은 학생보다 음주 가족력 검사에서 더 높은 점수를 보였다. 의존음주와 유해음주에는 성별과 데이트 폭력 가해 여부의 유의한 이원 상호작용이 발견되었다. 단순주효과 분석 결과, 데이트 폭력 가해 여부에 따른 의존음주 혹은 유해음주의 차이는 여성보다 남성에게서 더 현저하게 나타났다.