• 대한치과교정학회지
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• 제25권5호
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• pp.587-592
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• 1995

교정력에 의한 치아이동시 발생하는 골침착과 흡수의 골재형성 과정을 교정력의 크기와 적용기간에 따라 비교해 보고자 하였다. 성견 6마리를 대조군 1마리와 실험군 5마리로 나누어 실험군에서는 하악 제 1,2소구치 사이에 open coil spring을 장착해서 좌측에는 강한 힘(250-300g), 우측에는 약한 힘(50-75g)이 가해지도록 하여 12시간, 24시간, 3일, 1주, 2주에 각각 희생시켰다. 분리된 조직편에 대해 연X선 촬영을 하여 분석한 결과 다음과 같은 결과를 얻었다. 1. 견인측에서의 신생골 형성은 7일째부터 관찰되기 시작하여 14일째에는 광범위한 부위에서 방사선 불투과상을 관찰할 수 있었으나 힘의 크기에 따른 비교는 불가능하였다. 2. 압박측에서의 치조골 흡수는 3일째에 치조백선의 파괴로 나타나기 시작하여 7일째, 14일째에 걸쳐 증가되는 양상을 보였다.

• 한국산학기술학회논문지
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• 제21권6호
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• pp.574-583
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• 2020

본 연구는 인터넷을 통하여 반려견 식품을 구매하는 소비자의 반려견을 위한 지출 품목 및 비용, 반려견 푸드 선택 시 고려사항 등을 조사하였다. 성별로는 남성 39명(6.8%) 여성 532명(93.2%)으로 반려견 식품을 구입할 때 대부분 여성들이 인터넷 구매를 한다는 것을 알 수 있었다. 견주 연령대로는 20대 이하 184명(32.2%), 30대 241명(42.2%), 40대 이상 146명(25.6%)로 나타났다. 반려견의 연령을 보면 3세 이하가 200(35%)이고, 8세 이상 202(35.4%), 4~7세 169(29.6%)으로 나타났다. 반려견을 위한 구매빈도 주기는 1달 이상 주기로 구매한다고 가장 많이 답하였으며, 구매 식재료 중에서는 닭고기를 가장 많이 선호하는 것으로 나타났다. 월지출비용에서도 10만원 미만이 가장 높게 나타났으며, 반려견 푸드 주요 구입처로는 반려견 전문 온라인 쇼핑몰, 그 다음으로는 동물병원에서 구입한다고 하였다. 건강기능 향상을 위해서는 피부·모질개선을 가장 중요하게 여기고 있으며 그 다음으로 치아 뼈 형성, 소화력 개선 순으로 나타났다. 반려견 푸드 선택 시 전제품의 영양성분을 가장 고려할 사항이라고 여겼으며 그 다음으로는 인지도가 있는 브랜드 제품, 색·냄새·형상, 기능개선제품, 제품의 가격 순으로 나타났다. 따라서 반려견 푸드 신제품을 개발할 때는 전제품의 영양성분 뿐만 아니라 브랜드 제품, 색·냄새·형상, 영양밸런스, 기능개선제품, 제품의 가격 등을 고려해야 할 것으로 보여진다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2007년도 춘계학술대회 논문집
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• pp.223-225
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• 2007

Online models predicting roll force and forward slip of roughing mill was developed using nondimensional parameters. Using the effective inlet thickness, roll force model take into account the effect of inlet dog-bone shape of slab which take places after width reduction through edger rolling in roughing mill. The prediction accuracy of the proposed model is examined through comparison with measurements.

• Smart Structures and Systems
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• 제24권2호
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• pp.157-171
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• 2019

This study investigated the effects of the geometric parameters of superelastic shape memory alloy (SE SMA) fibers on the pullout displacement recovering and self-healing capacity of reinforced cementitious composites. Three diameters of 0.5, 0.7 and 1.0 mm and two different crimped lengths of 5.0 and 10.0 mm were considered. To provide best anchoring action and high bond between fiber and cement mortar, the fibers were crimped at the end to create spear-head shape. The single fiber cement-based specimens were manufactured with the cement mortar of a compressive strength of 84 MPa with the square shape at the top and a dog-bone shape at the bottom. The embedded length of each fiber was 15 mm. The pullout test was performed with displacement control to obtain monotonic or hysteretic behaviors. The results showed that pullout displacements were recovered after fibers slipped and stuck in the specimen. The specimens with fiber of larger diameter showed better displacement recovering capacity. The flag-shaped behavior was observed for all specimens, and those with fiber of 1.0 mm diameter showed the clearest one. It was observed that the length of fiber anchorage did not have a significant effect on the displacement recovery, pullout resistance and self-healing capacity.

• 한국임상수의학회지
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• 제25권5호
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• pp.408-410
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• 2008

A four months old, 3.6 kg intact female Miniature Dachshund dog was referred for non-weight bearing lameness at right hind limb due to car accident. On physical examination, the patient was non-weight bearing on the right hind leg and had moderate swelling in the proximal to middle tibia region. There was palpable crepitus. Radiographs revealed a slightly displaced, spiral, oblique fracture involving the proximal diaphyseal region of the right tibia. Fibular fracture was also noted. Internal fixation was performed to repair the fracture. Due to bowed shape of fractured tibia, it was not possible to apply K-wire, containing appropriate diameter ($60{\sim}80%$ of bone marrow diameter) for intramedullary fixation. We fixed the bowed tibia fracture using a smaller diameter (30% of bone marrow diameter) K-wire with cross pins and cerclage wires. Four weeks after the operation, radiographs demonstrated healing of the tibia fracture as well as the fibular fracture.

• Journal of Periodontal and Implant Science
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• 제42권2호
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• pp.50-58
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• 2012

Purpose: This study evaluated histologically the tissue responses to and the effects of a customized nano-hydroxyapatite (n-HA) block bone graft on periodontal regeneration in a one-wall periodontal-defect model. Methods: A customized block bone for filling in the standardized periodontal defect was fabricated from prefabricated n-HA powders and a polymeric sponge. Bilateral $4{\times}{\times}4{\times}5$ mm (buccolingual width${\times}$mesiodistal width${\times}$depth), one-wall, critical-size intrabony periodontal defects were surgically created at the mandibular second and fourth premolars of five Beagle dogs. In each dog, one defect was filled with block-type HA and the other served as a sham-surgery control. The animals were sacrificed following an 8-week healing interval for clinical and histological evaluations. Results: Although the sites that received an n-HA block showed minimal bone formation, the n-HA block was maintained within the defect with its original hexahedral shape. In addition, only a limited inflammatory reaction was observed at sites that received an n-HA block, which might have been due to the high stability of the customized block bone. Conclusions: In the limitation of this study, customized n-HA block could provide a space for periodontal tissue engineering, with minimal inflammation.

• 비파괴검사학회지
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• 제32권6호
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• pp.686-695
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• 2012

This paper proposes a noncontact thermography technique for fatigue crack evaluation under a cyclic tensile loading. The proposed technique identifies and localizes an invisible fatigue crack without scanning, thus making it possible to instantaneously evaluate an incipient fatigue crack. Based on a thermoelastic theory, a new fatigue crack evaluation algorithm is proposed for the fatigue crack-tip localization. The performance of the proposed algorithm is experimentally validated. To achieve this, the cyclic tensile loading is applied to a dog-bone shape aluminum specimen using a universal testing machine, and the corresponding thermal responses induced by thermoelastic effects are captured by an infrared camera. The test results confirm that the fatigue crack is well identified and localized by comparing with its microscopic images.

• 소성∙가공
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• 제23권3호
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• pp.145-150
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• 2014

Precision control of the slab is crucial for product quality and production economy in hot strip mills. The current study presents a new model for predicting width spread of a slab with a rectangular cross section during roughing. The model is developed on the basis of the extremum principle for a rigid plastic material and a three dimensional admissible velocity field. This model incorporates the effect of process variables such as the shape factor and the ratio of width to thickness. We compare the results of this model to 3-D finite element (FE) process simulations and also to results from a previous study.

• Design & Manufacturing
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• 제10권2호
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• pp.24-28
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• 2016

In this study, relevant to impact extrusion process of the rectangular batter case for electric vehicles, numerical and experimental analyses were conducted to reduce the earring defects induced in the unevenness of metal flow. Since the earring is caused by the non-uniform metal flow induced in the friction and aspect ratio in the bottom section. As a way to reduce the earring, variable land die concept was applied. In order to analyze numerically the complex metal flow by using commercial finite element package, DEFORM 3D, impact extrusion process was simplified in upsetting mode at bottom section and extrusion mode at land section. The impact extrusion experiments were conducted to verify the assessment of process parameter for impact extrusion. As results, variable land die which has longer longitudinal section makes reduce earring defects. In addition, it was confirmed that the effect that slug shape like dog-bone also can reduce the earring. This study is expected to be able to present the useful design guidelines for manufacturing the battery case.

• 한국임상수의학회지
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• 제34권5호
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• pp.318-324
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• 2017

The objective of this study was to establish kinematic reference ranges for the femorotibial (FT) joint and the patellofemoral (PF) joint in healthy small-breed dogs by measuring 3D kinematics at the walk. Single-plane fluoroscopy was used to image the stifle joints of five healthy beagle dogs while the dogs were walking. 3D bone models of the femur, patella, and tibia were reconstructed by computed tomography scanning of the beagle dogs' hind limbs. The shape-matching technique was used to measure kinematic data from the fluoroscopic images and the 3D bone models. The cranial translation of the tibia during walking was inversely proportional to the FT joint flexion. There were significant correlations between the patellar motion and the tibial motion. The FT joint flexion had a strong correlation with the patellar proximodistal translation and flexion. Additionally, the tibial mediolateral translation had a strong correlation with the patellar shift and tilt. In this study, normal in vivo 3D FT joint and PF joint kinematics were demonstrated, and the average kinematic parameters were determined in walking beagle dogs.