• 대한치과보철학회지
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• 제56권1호
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• pp.8-16
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• 2018

목적: 본 연구의 목적은 디지털 소프트웨어를 이용하여 제작된 수술용 스텐트를 이용하여 지지 형태에 따른 수술용 스텐트의 정확성을 분석하는 것이다. 재료 및 방법: 총 5세트의 치아모형에 대하여 양측에 지대치가 있는 치아지지형 무치악 모델과 근심에만 지대치가 있는 치아-조직 지지형 무치악 모델을 제작하였다. 모델을 스캐닝을 시행하고, 전산화 단층 촬영을 실시하여 In2Guide 소프트웨어를 이용하여 전산화 단층 촬영술의 정보와 모델 스캐닝 정보를 중첩하여 임플란트 고정체(USII, $4{\times}10mm$, Osstem, Seoul, Korea)에 대한 가상적인 위치배열을 실시하고 수술용 스텐트 제작하였다. DMAX 수술 키트을 사용하여 임플란트 고정체를 식립하였다. 식립후 전산화 단층 촬영을 실시하여 찍어 술전에 계획된 임플란트와 실제 식립된 임플란트 사이에 오차(angle difference, coronal difference, apical difference)를 측정하여 통계분석을 시행하였다. 결과: 악궁에 따른 정확도 결과에서 하악이 전반적으로 각도, 길이오차의 값이 작게 나타났으나 이는 통계적 유의성이 없었다. 스텐트의 지지 형태에 따른 정확도 결과에서 치아지지형 스텐트가 치아-조직지지형 스텐트보다 길이오차와 각도오차의 값이 통계적으로 유의하게 작은 값을 보였다. 결론: 악궁(상악, 하악)은 수술용 스텐트의 정확도에 영향을 미치지 않았으며, 치아 지지형 스텐트는 치아-조직지지형 스텐트보다 더 적은 오차를 보여 주었다.

• 구강회복응용과학지
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• 제17권4호
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• pp.245-256
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• 2001

The purpose of this study is to analyze the mechanical stress and displacement on the jaws during the simulated bilateral clenching task on the three-dimensional finite element model of the dentated skull with unilateral molar loss. For this study, the computed tomography(G.E.8800 Quick, USA) was used to scan the total length of human skull in the frontal plane at 2.0mm intervals. The fully assembled finite element model consists of the articular disc, maxilla, mandible, teeth, periodontal ligament and cranium. The FE model was used to simulate the bilateral clenching in intercuspal position. The loading condition was the force of the masseter muscle exerted on the mandible as reported by Korioth et al. degrees of freedom of the zygomatic region where the masseter muscle is attached were fixed as restraints. In order to reflect the actual action of the muscles force, the displacement of the region was attached where the muscle is connected to the temporal bone and restraint conditions were given values identical to values at the attachment region of the masticatory muscle but with the opposite direction of the reaction from when the muscle force is acted on the mandible. Although the mandible generally has higher displacement and von Mises stress than the maxilla, its mandibular corpus on the molar-loss side has a higher stress and displacement than the molar-presence side. Because the displacement and von Mises Stress was the highest on the lateral surface of mandibular corpus with molar loss, the stress level of the condyle on the molar-loss side is greater than that of the molar-presence side, which in turn caused the symphysis of the mandible to bend. In conclusion, the unilateral posterior bite collapse with molar loss under para-functional activities such as bruxism and clenching can affect the stress concentration on the condyle and mandibular corpus. It is therefore necessary to consider the biomechanical function of dento-skeleton under masticatory force while designing the occlusal scheme of restoration on alveolar bone with the posterior collapse.

• 전자공학회논문지
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• 제53권12호
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• pp.169-174
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• 2016

본 연구에서는 실제적인 환자의 모델을 바탕으로 가상현실 기반의 수술환경을 제작하는 방법에 대한 고찰과 함께 치과 임플란트 수술 술기를 배울 수 있는 가상현실을 활용한 수술 모델에 대한 평가를 시행하고자 한다. 환자의 안면 해부학적 모델은 실제 환자의 CT 데이터를 바탕으로 안면부위 골에 대한 삼차원 모델을 먼저 완성한 후 각각의 근육을 표현하고 안면부에 대한 삼차원 스캔 그리고 치아의 3차원 스캔 후 모델링을 통해 각각의 해부학적 구조물을 표현하였다. Unity3D를 활용해 단계별 시나리오를 게임으로 구성하였다. 처음 절개를 시행하는 단계에서부터 환자의 현재 상태에 필요한 상악동 거상술에 대한 술기를 표현하고, 임플란트 식립과정 그리고 골이식술을 하는 과정을 단계별로 포함하였다. 단계별로 중요한 과정의 효과적인 습득을 위해 HMD(Head Mount Display) 및 Leap motion과 연동하여 3차원 모델에 기구를 위치시키고 수술행위를 재현해볼 수 있게하여 몰입감을 높이면서 실제 수술을 하고있는 느낌을 재현하고자 하였다. 총 20명의 수련의를 대상으로 가상현실 시뮬레이션을 수행한 후에 설문조사를 시행하였다. 임플란트 수술 교육 프로그램은 치과 대학생들과 수련의들의 교육 도구로서 수술 술기를 습득하고 평가하는데 사용할 수 있는 가능성을 보여주었다. 통상적으로 수술 술기 교육 방법이 많지 않은 현실에서 HMD 와 Leap motion이라는 비교적 저렴한 기기를 이용하여 몰입감을 높일 수 있는 가상현실 기반의 수술 교육은 장점이 있다고 말할 수 있다.

• 치과방사선
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• 제28권2호
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• pp.387-413
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• 1998

Image resampling is of particular interest in digital radiology. When resampling an image to a new set of coordinate, there appears blocking artifacts and image changes. To enhance image quality, interpolation algorithms have been used. Resampling is used to increase the number of points in an image to improve its appearance for display. The process of interpolation is fitting a continuous function to the discrete points in the digital image. The purpose of this study was to determine the effects of the seven interpolation functions when image resampling in digital periapical images. The images were obtained by Digora, CDR and scanning of Ektaspeed plus periapical radiograms on the dry skull and human subject. The subjects were exposed to intraoral X-ray machine at 60kVp and 70 kVp with exposure time varying between 0.01 and 0.50 second. To determine which interpolation method would provide the better image, seven functions were compared; (1) nearest neighbor (2) linear (3) non-linear (4) facet model (5) cubic convolution (6) cubic spline (7) gray segment expansion. And resampled images were compared in terms of SNR(Signal to Noise Ratio) and MTF(Modulation Transfer Function) coefficient value. The obtained results were as follows ; 1. The highest SNR value(75.96dB) was obtained with cubic convolution method and the lowest SNR value(72.44dB) was obtained with facet model method among seven interpolation methods. 2. There were significant differences of SNR values among CDR, Digora and film scan(P<0.05). 3. There were significant differences of SNR values between 60kVp and 70kVp in seven interpolation methods. There were significant differences of SNR values between facet model method and those of the other methods at 60kVp(P<0.05), but there were not significant differences of SNR values among seven interpolation methods at 70kVp(P>0.05). 4. There were significant differences of MTF coefficient values between linear interpolation method and the other six interpolation methods (P< 0.05). 5. The speed of computation time was the fastest with nearest -neighbor method and the slowest with non-linear method. 6. The better image was obtained with cubic convolution, cubic spline and gray segment method in ROC analysis. 7. The better sharpness of edge was obtained with gray segment expansion method among seven interpolation methods.

• 한국과학교육학회지
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• 제33권7호
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• pp.1471-1485
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• 2013

본 연구에서는 변별과제를 해결하는 동안 초등학생의 안구운동을 분석하여 발견적 주의모델을 개발하였다. 연구 참여자는 초등학교 6학년 20명이었고 모두 부모의 동의 절차를 거친 자발적인 지원자였다. 본 연구에 사용된 변별과제는 권재술과 김범기(1994)가 개발한 과학탐구능력 검사지에서 아이트래킹으로 실험 가능한 두 과제를 선택하였다. 학생들의 안구운동의 수집은 SMI사의 iView X TM RED 120 Hz를 사용하였고 실험설계와 분석은 동사의 Experiment 3.2와 BeGaze 3.2의 소프트웨어를 사용하였다. 학생들의 모든 안구운동은 응시시간에 대한 정량적인 분석과 문제해결과정에서 학생개인의 인지사고과정을 추론하는 정성적인 분석과정을 거쳤다. 본 연구결과는 다음과 같다. 첫째, 학생들의 실험 자료의 시각정보의 복잡한 정도에 따라 인지적 부담이 가중되었고 대상을 재인하는 관점 의존적이었다. 둘째, 실험 자료의 제시로 상향식주의가 발화되었고 하향식주의에 의해 의도적이고 목표지향적인 안구운동과 혼란 주의에 의한 안구운동을 구분할 수 있었다. 이를 토대로 인간의 주의와 안구운동을 도식할 수 있었다. 셋째, 압축된 시선흐름(compressed scan-path)을 분석하여 학생들의 문제해결전략을 도출하였다. 넷째, 본 연구의 결과를 통해 발견적 주의 모델(HAM)을 개발하였다. 이 발견적 주의 모델은 앞으로 학생들의 문제해결과정을 분석하는데 효과적인 분석관점을 제공할 것으로 기대된다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2008년도 춘계종합학술대회 A
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• pp.579-584
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• 2008

고속철도 차륜의 미소결함을 고속 고공간 분해 능으로 측정할 수 있는 새로운 비파괴검사법이 요구되고 있다. 본 연구는 종래의 스캔형 자기카메라를 개선하여, 다중증폭회로와 결함표시를 위한 펄스 발생기를 장착한 신호처리회로를 제안한다. 홀센서를 선형으로 배열하고, 배열의 직각방향으로 차륜이 정속으로 회전하게 하면, 차륜의 답면을 검사할 수 있다. 각각의 홀전압을 증폭하고, AD변환기를 통하여 $\mu$-processor에 의하여 시간에 따른 전압차, 즉 ${\partial}V_H/{\partial}t$를 연산한다. ${\partial}V_H/{\partial}t$가 결함의 존재를 의미하는 비교치보다 클 때 pulse 신호가 발생하여 결함을 지시한다. 휠 시험편을 이용하여 제안된 방법을 검증하였다.

• Journal of Korean Neurosurgical Society
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• 제30권6호
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• pp.749-754
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• 2001

Objective : The IDET(Intradiscal electrothermal therapy) appears as a new therapeutic modality for intractable discogenic back pain. We carried out a prospective study to analyze and evaluate the therapeutic effects of IDET. Methods & Results : During a six month period, we performed IDET in 39 patients with chronic low back pain using RITA Model 30 Electrosurgical device. The patients included 21 men and 18 women. The mean patient age was 50.2 years(range 21-73 years). All patients underwent preoperative plain radiography and MRI for excluding non-discogenic back pain. We conducted discography-CT to reveal painful discs in all patients. During the study, we measured intradiscal pressure subjectively. The area of annular tear, which identified with post-discography CT scan, was coagulated in $90^{\circ}C$ of temperature for 15 minutes. Of the 17 patients who were followed up more than three months after surgery, the 10 patients(58.8%) experienced clinical improvement. Three patients had high intradiscal pressure on discography, other three patients had loss of disc height more than 30% of normal on plain radiography, and one patient suffered from postoperative epidural abscess. All of these patients were included in the remaining no improvement group(41.2%). Conclusion : The IDET procedure could be an alternative modality for discogenic back pain. It appears that a patient who has low intradiscal pressure on discography and intact disc height on plain radiography is considered a good candidate for IDET.

• 한국의류산업학회지
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• 제14권4호
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• pp.607-613
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• 2012

This study develops a Hanbok Jeogori pattern for middle-aged women with a 3D virtual-twin and virtual-garment simulation system. The including criteria for subjects in this study was a focus on women in their 50s, and a total of 345 females satisfying them were enrolled for 3D virtual model. Comparative Jeogori pattern, Baik & Choi's(2004) pattern, was selected for the development of Jeogori pattern. The results were: first, a new Jeogori pattern considerate of middle-aged women was developed. The basic numerical formula were: Front and back bust girth B/4+1.5, armhole depth B/4, sleeve width B/4, goedae width B/10-1.5 and git width 5.5. Second, according to the results of the new Jeogori patterns appearance evaluation, the new Jeogori pattern scored higher than the existing pattern in silhouette and ease amount, this confirmed that the new Jeogori pattern is appropriate for middle-aged women. Virtual models of production through data from 3D body scan, pattern draft, and virtual garment digital program were applied to a prototypic design method to enhance the fitness of ready-made Hanbok garments. This study serves as important basic data for ensuing studies that may utilize 3D Virtual Garment Simulation System with 2D patterns and for the future 3D Pattern Production Program development of Hanbok patterns.

• Asian-Australasian Journal of Animal Sciences
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• 제23권3호
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• pp.287-291
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• 2010

The purpose of this study was to detect quantitative trait loci (QTL) for growth and carcass quality traits on BTA6 in a population of Hanwoo cattle. Three hundred and sixty one steers were produced from 39 sires that were sired by 17 grandsires in the two Hanwoo farming branches of the National Livestock Research Institute of Korea, between Spring 2000 and Fall 2002. DNA samples were collected for all of the steers, sires and grandsires, and the phenotypes for six growth and carcass quality traits were measured at 24 months of age. Twelve microsatellite markers were chosen on BTA6 and a linkage map was constructed by using seven of the twelve markers. Then, a chromosome-wide QTL scan was performed by applying an Animal Model, in which effects of QTL alleles within the grand sires were fitted as a random term. Three QTL were detected at the 5% chromosome-wise level for backfat thickness, average daily gain, and final weight. The most likely positions for the QTL were in the proximal region, i.e. 0 cM, 35 cM, and 63 cM, respectively. Also, another QTL for longissimus dorsi muscle area was detected at the 10% chromosome-wise level at 67 cM. These results were, in general, consistent with our previous report, in which candidate gene analyses showed that a SNP near ILSTS035 flanked by BM4621 (62.5 cM) and BMS2460 (81.3 cM) was associated with final weight, carcass weight, average daily gain, and longissimus dorsi muscle area in the same Hanwoo population.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.1480-1484
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• 2003

This paper presents the design and development of network for housing estate security system. The system can cover up to 961 houses which can be up to 1,200 meters long transfer rate of 9,600 bps. This system uses checking and warning the abnormal situation. More over this system has ability to control switch on/off the electrical equipment in the house via AC line control system. The system consists of 4 parts. The first part is a security system of each house using MCS-51 microcontroller as a central processing unit scan 32 sensors and control 8 appliances and send alarm. The MCS-51 microcontroller received control signal via telephone used DTMF circuit. The second part is distributed two levels master/slave network implementing after RS-485 serial communication standard. The protocol its base on the OSI (Open Systems Interconnection) 7 layers protocol model design focus on speed, reliability and security of data that is transferred. The network security using encrypt by DES algorithm, message sequence, time stamp checking and authentication system when user to access and when connect new device to this system. Flow control in system is Poll/Select and Stop-and-Wait method. The third part is central server that using microcomputer which its main function are storing event data into database and can check history event. The final part is internet system which users can access their own homes via the Internet. This web service is based on a combination of SOAP, HTTP and TCP/IP protocols. Messages are exchanged using XML format [6]. In order to save the number of IP address, the system uses 1 IP address for the whole village in which all homes and appliance in this village are addressed using internal identification numbers. This proposed system gives the data transfer accuracy over 99.8% and maximum polling time is 1,120 ms.