• 대한두개안면성형외과학회지
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• 제10권2호
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• pp.86-90
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• 2009

Purpose: Inferior blow-out fracture is the common facial fracture. Unsatisfactory functional and aesthetic outcomes are frequent when it is treated inappropriately. If fractures are extended and reach the posterior end of orbital floor, enophthalmos frequently followed as complication. The purpose of this study was to evaluate reduction technique of extensive inferior blow-out fracture with ballooning of foley catheter through endoscopic transnasal approach and implantation of $Medpor^{(R)}$ through subciliary approach. Methods: A retrospective study was performed on 14 patients with extensive inferior blow-out fracture who underwent ballooning of foley catheter through endoscopic transnasal approach with implantation of $Medpor^{(R)}$ through subciliary approach. Patients were operated from May 2005 to November 2007. Data for 14 patients were acquired from patient's charts. Preoperative and postoperative data for enophthalmos, diplopia, limitation of extraocular motion were reviewed. Preoperative and postoperative CT scan were also checked. The patients were followed up from 4 to 18 months. Results: The enophthalmos was corrected in all patients. Among 7 patients with diplopia preoperatively, diplopia was resolved in three patients postoperatively. The diplopia persisted in four patients and two of them also had limitation of extraocular motion postoperatively. The limitation of extraocular motion occurred in seven patients preoperatively. But five patients recovered after operation immediately. These symptoms were resolved about three months after the operation. Conclusion: The ballooning of foley catheter through endoscopic transnasal approach with implantation of $Medpor^{(R)}$ through subciliary approach can be considered one of the appropriate technique for extensive inferior blowout fracture.

• 대한두개안면성형외과학회지
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• 제16권3호
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• pp.114-118
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• 2015

Background: The reduction of orbital blowout fracture primarily aims to normalize the extra-ocular movement by returning the herniated orbital soft tissue into the original position, and to prevent enophthalmos by normalizing the orbital cavity volume. We introduce a balloon catheter-assisted orbital floor reduction technique. Methods: A retrospective review was performed for all patients with orbital floor fracture who underwent the technique described in the main body of this text. Medical records were reviewed for demographic data, clinical presentation and course, degree of enophthalmos, intraorbital volume on computed tomography scan, and postoperative outcomes. The enophthalmos and intraorbital volume of the injured site were compared to the uninjured eye and orbit. Results: The review identified 14 patients (11 male, 3 female). The mean preoperative difference in en-exopthalmos was 2.13 mm, while the mean orbital volume was 116%. The mean postoperative difference in en-exophthalmos had improved to 0.61 mm with a mean orbital volume of 101.85%. At the time of catheter removal at 10 days, three patients experienced diplopia (n=1), extra-ocular movement disorder (1), or enophthalmos (1). All of these had resolved by the 6-month follow-up visit. Conclusion: Balloon catheter-assisted reduction of the orbital floor fractures was associated with improvements in intraorbital volume and enopthalmos in the 14 patients. Notable complications included diplopia, enophthalmos, and limited extra-ocular movement, all of which were transient in the early postoperative period and had resolved by 6-month follow up.

• Clinics in Shoulder and Elbow
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• 제17권4호
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• pp.159-165
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• 2014

Background: Kirschner's wire (K-wire) transfixation and locking hook plate fixation techniques are widely used in the treatment of acute acromioclavicular joint (ACJ) dislocation. The purpose of this study was to compare the clinical and radiologic outcomes between K-wires transfixation and a locking hook plate fixation technique. Methods: Seventy-seven patients with acute ACJ dislocation managed with K-wire (56 shoulders) and locking hook plate (21 shoulders) were enrolled for this study. The mean follow-up period was 61 months. Results: At the last follow-up, the shoulder rating scale of the University of California at Los Angeles (UCLA) was higher in patients treated with locking hook plate than with K-wires ($33.2{\pm}2.7$ vs. $31.3{\pm}3.4$, p=0.009). In radiologic assessments, coracoclavicular distance (CCD) (7.9 mm vs. 7.7 mm, p=0.269) and acromioclavicular distance (ACD) (3.0 mm vs. 1.9 mm, p=0.082) were not statistically different from contralateral unaffected shoulder in locking hook plate fixation group, but acromioclavicular interval (ACI) was significant difference. However, there were significant differences in ACI, CCD, and ACD in K-wire fixation group (p<0.001). Eleven complications (20%) occurred in K-wire transfixation group and 2 subacromial erosions on computed tomography scan occurred in locking hook plate fixation group. Conclusions: ACJ stabilization was achieved in acute ACJ dislocations treated with K-wires or locking hook plates. Locking hook plate can provide higher UCLA shoulder score than K-wire and maintain CCD, and ACD without ligament reconstruction. K-wire transfixation technique resulted in a higher complication rate than locking hook plate.

• 비파괴검사학회지
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• 제24권2호
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• pp.151-157
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• 2004

초음파검사는 재료의 표면 또는 내부에 존재하는 불 연속부를 검출하기 위해, 초음파를 재료에 전달시켜 검사하는 비파괴검사법의 일종이다. 이러한 일반 초음파검사 방법 및 일반 결함평가 방법은 복잡한 형상에서 반사되는 신호로부터 결함을 구분하기가 어려워 결함의 평가 및 검사결과에 신뢰성이 떨어지고 있는 실정이다. 따라서 이러한 crack성 결함의 발생 가능성이 높으나 기존의 초음파검사 방법으로는 결함 판별에 어려움이 있는 설비에서의 검사방법 및 결함평가 방법의 제고가 필수 불가결한 실정이다. 본 연구에서는 위상배열 초음파를 사용하여 크랙 검출능력이 높고 길이 평가가 가장 정확한 방사각도를 규명하고, 주요발전설비중 하나인 터빈에 적용하였다. 기존의 초음파 검사 방식이 아닌 위상배열 초음파를 이용하여 결함의 크기를 평가할 수 있는 신 기법 및 이를 이용하여 터빈 블레이드 루트부 내에 존재하는 미세 결함에 대하여 크기평가 방법 및 결함탐지 방법에 대하여 고찰하였다.

• 대한두개안면성형외과학회지
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• 제11권1호
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• pp.1-6
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• 2010

Purpose: Many surgical approaches for reconstruction of blow out fracture have been introduced, which include subciliary incision, transconjunctival incision and transcaruncular incision. Recently endoscopic approach has been attempted. This study was intended to show the effectiveness of the approach through transconjunctival incision combined with transnasal reduction in reconstructing blow out fracture to its original position. Methods: Medical recoreds of 43 patients from March 2008 to March 2009 who underwent surgery for orbital fracture were reviewed, retrospectively. All fractures were operated through transconjuctival incision approach combined with transnasal reduction. The average follow-up period was 10.1 months. To evaluate the surgical outcomes of orbital fracture, we performed CT of the facial bone before and after the surgery. In addition, preoperative and postoperative data of enophthalmos, diplopia and the limitation of extraocular motion was assessed with physical examination. Results: Post-operative CT scan of 43 patients assured that the bone fragments of the orbital fractures were restored to their original positions. Although a few patients developed postoperative transient diplopia or impairment of ocular movement, most of the patients recovered during the follow-up period without complication. Conclusion: From this study, we were able to demonstrate the effectiveness of the transnsasal reduction technique combined with the approach through transconjunctival incision. This technique can be considered as very useful means of repairing orbital fracture. It is not only easy to perform but also it can minimize the damage to the orbital bone. Furthermore, it can restore the fracture to its original position as much as possible.

• 한국정보과학회논문지:소프트웨어및응용
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• 제30권7_8호
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• pp.610-617
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• 2003

비디오 데이타베이스에서 유사도 정합은 비디오 클러스터링과 비디오 라이브러리 등과 같은 많은 새로운 응용분야에서 중요성이 증가하고 있다. 대용량 데이타베이스에서 효과적인 접근을 제공하기 위하여 다양한 공간과 시간에 대한 특징치를 이용한 비디오 인덱싱 분야의 많은 연구노력이 있어왔다. 그러나 대부분의 기존 방법들은 순차적인 정합방법 또는 메모리 기반의 역 파일 기법 등에 의존하므로 대용량 데이타베이스에는 적합하지 않다. 이러한 문제를 해결하기 위하여 본 논문에서는 효과적이고 스케일 조정가능한 인덱싱 기법을 제안하기 위하여, 문자열 정합을 위해 제안된 trio를 인덱스 구조로 이용하였다. 인덱스 구성을 위하여 윈도우 순서 휴리스틱을 이용하여 각 프레임을 기호 시퀀스로 변환하고, 기호 시퀀스의 집합으로부터 디스크 상주 trio를 구성하였다 질의 처리를 위하여 trio 상에서 깊이-우선 검색과 시간 축분할을 실시하였으며, 제안한 방법의 성능을 검증하기 위하여 실제와 합성 데이터 집합에 대한 실험을 수행하였다. 제안한 방법은 지속적으로 순차적 스캔 방법보다 우수한 성능을 보였고, 성능이득은 대용량 비디오 데이타베이스에서도 유지되었다.

• 대한전자공학회논문지
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• 제26권1호
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• pp.69-77
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• 1989

POS시스템에서 사용되는 바토드 심볼 판독을 위한 홀로곤 스캐너를 개발하였다. 제작된 시스템은 주사 광학부, 광 검출부, 비디오 신호 처리부, 그리고 전치 처리기로 구성되어 있으며, 기존의 다면경을 이용한 바코드 스캐너에 비하여 광학부가 간단하고 바코드 판도면에서 향상된 성능을 얻을 수 있었다. 위치가 변화된 바코드 라벨위에 이루어지는 고밀도 스캔 패턴을 모든 방향에서 판독하기 위하여 실시간으로 디코딩을 수행할 수 있는 새로운 로직을 제안하여 하드웨어와 클락 주파수를 줄임으로써 보다 효율적인 시스템을 구성하였다. 실험 결과, 제작된 시스템은 빠른 처리속도와 기울어진 심볼에 대해서도 좋은 판독율을 나타내었다.

• The Journal of Advanced Prosthodontics
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• 제10권4호
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• pp.265-270
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• 2018

PURPOSE. The purpose of this in vitro study was to evaluate the accuracy of a new implant impression technique using bite impression coping and a dual arch tray. MATERIALS AND METHODS. Two implant fixtures were placed on maxillary left second premolar and first molar area in dentoform model. The model with two fixtures was used as the reference. The impression was divided into 2 groups, n=10 each. In group 1, heavy/light body silicone impression was made with pick up impression copings and open tray. In group 2, putty/light body silicone impression was made with bite impression copings and dual arch tray. The reference model and the master casts with implant scan bodies were scanned by a laboratory scanner. Surface tessellation language (STL) datasets from test groups was superimposed with STL dataset of reference model using inspection software. The three-dimensional deviation between the reference model and impression models was calculated and illustrated as a color-map. Data was analyzed by independent samples T-test of variance at ${\alpha}=.05$. RESULTS. The mean 3D implant deviations of pick up impression group (group 1) and dual arch impression group (group 2) were 0.029 mm and 0.034 mm, respectively. The difference in 3D deviations between groups 1 and 2 was not statistically significant (P=.075). CONCLUSION. Within limitations of this study, the accuracy of implant impression using a bite impression coping and dual arch tray is comparable to that of conventional pick-up impression.

• The Journal of Advanced Prosthodontics
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• 제7권4호
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• pp.294-302
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• 2015

PURPOSE. The purpose of this study was to verify the clinical-feasibility of additive manufacturing by comparing the accuracy of four different manufacturing methods for metal coping: the conventional lost wax technique (CLWT); subtractive methods with wax blank milling (WBM); and two additive methods, multi jet modeling (MJM), and micro-stereolithography (Micro-SLA). MATERIALS AND METHODS. Thirty study models were created using an acrylic model with the maxillary upper right canine, first premolar, and first molar teeth. Based on the scan files from a non-contact blue light scanner (Identica; Medit Co. Ltd., Seoul, Korea), thirty cores were produced using the WBM, MJM, and Micro-SLA methods, respectively, and another thirty frameworks were produced using the CLWT method. To measure the marginal and internal gap, the silicone replica method was adopted, and the silicone images obtained were evaluated using a digital microscope (KH-7700; Hirox, Tokyo, Japan) at 140X magnification. Analyses were performed using two-way analysis of variance (ANOVA) and Tukey post hoc test (${\alpha}=.05$). RESULTS. The mean marginal gaps and internal gaps showed significant differences according to tooth type (P<.001 and P<.001, respectively) and manufacturing method (P<.037 and P<.001, respectively). Micro-SLA did not show any significant difference from CLWT regarding mean marginal gap compared to the WBM and MJM methods. CONCLUSION. The mean values of gaps resulting from the four different manufacturing methods were within a clinically allowable range, and, thus, the clinical use of additive manufacturing methods is acceptable as an alternative to the traditional lost wax-technique and subtractive manufacturing.

• 한국의류산업학회지
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• 제13권4호
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• pp.590-599
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• 2011

The purpose of this study is to classify body types into different groups based on 3D scanned data, and identify the representative body shapes that most frequently appear in the groups. A high frequency range was defined based on body measurement data, and representative shapes were identified based on body scan data of women aged 18-24. The major findings of this study are as follows. First, the three typical types of height, bust and drop mixes among Korean women aged 18-24 are as follows:) 155-88-N,) 160-82-A, and 165-85-A. Regarding the body type, the A and N types frequently appeared, while the H type was rare. Second, among the subjects of the high-frequency groups, upright bodies were selected as sample models and were used for morphing. An adjustment was made to the morphing results to reflect the body characteristics of the sample models evenly. Third, to verify the morphing results, the body sizes of the sample models and the created models were compared. The result showed that, the sizes were close to the average size of the sample models. Fourth, to verify whether the morphing processes adequately reflected the features of the body shapes, cross-section models of key body parts were made and the degree of representativeness was determined.