• 한국HCI학회:학술대회논문집
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• 2006.02a
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• pp.75-81
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• 2006

슬관절 전치환술은 관절염이나 사고로 인해 일상적인 활동의 제약을 받는 환자의 슬관절을 인공 관절로 대체함으로써 본래의 기능을 복원하고자 하는 수술이다. 이 수술은 인공 관절의 위치 및 정렬에 매우 민감하게 영향을 받기 때문에 수술이 잘못되는 경우 정렬 이상으로 인한 해리, 삽입물의 파손, 인공 슬관절 주위 골절, 슬개골 탈구, 굴곡 각도의 제한 등의 증상이 발생할 수 있다. 현재의 인공 관절은 임상에 적용되는 다양한 인공 관절 중에서 적당한 형상의 관절을 선택하여 시술되고 있지만 환자의 골 형상에 정확히 일치하는 인공 관절 선택의 어려움 때문에 종종 시술 후 부작용이 발생한다든지 심지어는 재수술을 해야 될 경우도 발생하게 된다. 본 논문은 Mechanical CAD 소프트웨어인 CATIA에서 제공하는 절단, Assembly, Analysis, Kinematic Simulation 기능 등을 이용하여 가상 수술을 수행하는 과정을 보여준다. 슬관절 전치환술 과정을 그대로 재현하여 절단량과 절단각을 결정하고 환자의 골격 형상에 적합한 최적의 인공 관절을 실제 수술 전에 미리 선정할 수 있다. CAD 시스템을 이용함으로써 외과의들이 실제 수술 시에 시행착오법을 통해 인공 관절을 선택하는 과정을 줄이고 수술의 정확도를 높일 수 있다. 향후 ADAMS나 ANSYS와 연계하여 수술 후 동작이나 하중을 분석할 수 있으며, 수술 과정에 대한 교육용으로 활용될 수 있다.

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.11a
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• pp.42.2-42.2
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• 2009

인체의 치아 및 뼈는 무기질 성분과 단백질로 구성되어 있다. 생체세라믹스의 일종인 수산화아파타이트(Hydroxyapatite, HA; $Ca_{10}(PO_4)_6(OH)_2$)는 결정학적, 화학적으로뼈의 무기질 성분과 거의 유사하여 실제 체내에 들어가면 주위 뼈와 화학적 반응을 하여 단단한 결합을 이루는 생체활성(bioactive)을 가진 것으로 알려져 있다. 또한, 인산삼칼슘(Tri-Calcium Phosphate, TCP; $Ca_3(PO_4)_2$)은 체내에 이식 시 체액에 용해되어 신생골을 유도하는 생체흡수성(bioresorbable) 세라믹스로 알려져 있다. 상기 2종류를 포함한 인산칼슘계 화합물은 우수한 생체친화성에도 불구하고 역학 특성이 낮아, 하중을 거의 받지 않는 분야에만 사용되고 있는 실정이며, 하중을받는 분야(load-bearing part)에 적용하기 위해서는 고강도/고인성의 세라믹스와의 micro-composite이나 인산칼슘계화합물을 금속 표면에 코팅한 macro-composite의 형태로 사용되고 있다. 하중을 거의 받지 않는 분야, 예를 들어 치아 결손부를 보충할 dental shot과 같은 인산칼슘계 다공질 골충전재의 경우에도 취급 시 잘게 파손되는 문제점이 있어 치과의사들이 어려움을 호소하고 있는 실정이다. 본 연구에서는 HA, TCP의 역학특성을 증진시키고자 소결 공정 제어를 통하여 미세조직을 변화시켰으며, 미세조직 변화에 따른 세포반응성을 골포세포주를 이용하여 평가하였다.

• Clinics in Shoulder and Elbow
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• v.1 no.1
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• pp.118-122
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• 1998

This study evaluated the development of osteolysis of Kudo total elbow arthroplasties according to the fixation with or without cement. Twenty-four elbows of nineteen patients of rheumatoid arthritis underwent total elbow arthroplasty from 1986 to 1993. The patients were followed for an average of 42 months ranging from 36 months to 59 months. In cemented humeri, 1 of 13 (7.7%) showed osteolysis. In the humeri of cementless fixation, 5 of II (45.5%) revealed osteolysis, representing higher rate compared to cement fixation (P<0.05). In the ulna, osteolysis was identified in none of 16 (0%) of cement fixation, which was significantly less than the incidence of osteolysis in cement less fixation (3 of 8,37.5%) (P<0.01). It was concluded that the cement fixation result in less osteolysis than the cementless fixation in Kudo type total elbow arthroplasty.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.3 s.168
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• pp.162-169
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• 2005

The functional external fixator system fur bone deformity near joints in legs using the worm gear was developed for curing the difference angles in fracture bone and the lengthening bar for curing the difference length in fracture bone. Both experiments and FE analysis were performed to compare the elastic stiffness in several loading modes and to improve the functional external fixator system for the bone deformity. The FE model using the compressive and bending FE analysis was applied to the FE analysis due to the angle differences. The results show that the compressive stiffness value in experiment was 175.43N/mm; the bending stiffness value in experiment was 259.74N/mm; compressive stiffness value in FEM was 188.67N/mm; bending stiffness value in FEA was 285.71N/mm. The errors between experiments and FEA were less than 10%. The maximum stress (157MPa) to the angle of clamp was lower than the yield stress (176.4MPa) of SUS316L. The stiffnesses in both axial compressive and bending of the new fixator are about 2 times higher than other products except EBI (2003).

• The Journal of the Korean bone and joint tumor society
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• v.1 no.1
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• pp.17-22
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• 1995

From Sept. 1986 to Dec. 1992, seventy three cases of Enneking's stage IIB osteosarcoma of extremities, which were proved histologically, took neoadjuvant chemotherapy and completed our protocol. Their average age was 16.7 years(7 to 57). For neoadjuvant chemotherapy, 37 cases took high dose methotrexate(HDMTX)-adriamycin(ADR)-cisplatin(CDDP) regimen(HDMTX group) and 36 cases took ADR-CDDP(ADR-CDDP group). The average follow up was 17 months(2-63). According to Kaplan-Meier's plot, 5-year continuously disease free survival for whole 73 cases of neoadjuvant group was 45.2%, for HDMTX group 68.4%, for ADR-CDDP group 26.6%. There was significant stastical difference between these two groups(p<0.001), with log-rank test. There can be a different survival according to the chemotherapeutic protocols. Better results can be achieved through refined protocol and effective chemotherapeutic agents.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.1248-1251
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• 2004

The functional external fixator system for bone deformity near joints in legs using the worm gear was developed for curing the difference angles in fracture bone and the lengthening bar for curing the difference length in fracture bone. Both experiments and FE analysis were performed to compare the elastic stiffness in several loading modes and to improve the functional external fixator system for bone deformity near joints in legs. The FE model using the compressive and bending FE analysis was applied the FE analysis due to the angle differences. The results show that the compressive stiffness value in experiment was 175.43N/mm, the bending stiffness value in experiment was 259.74N/mm, compressive stiffness value in FEM was 188.67N/mm, bending stiffness value in FEA was 285.71N/mm. The errors between experiments and FEA were less than 10％. The maximum stress (157MPa) to the angle of clamp was lower than the yield stress (176.4MPa) of SUS316L. The stiffnesses in both axial compressive and bending of the new fixator are about 2 times higher than other products except EBI (2003).

• Journal of Biomedical Engineering Research
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• v.33 no.4
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• pp.207-212
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• 2012

It is widely known that sciatic nerve injury (SNI) can negatively affect the biomechanical characteristics of the musculoskeletal system. However, there were no studies that evaluated and compared denervated side with another side limb at the same time. In this study, sixteen male 12-week-old mice were allocated into two groups: HEMI (Right Sciatic nerve denervated) and CON (Control). Both limbs were scanned using micro-CT at 0 week and 4 weeks. There were significant differences in relative variation (RV) of BMD and all structural parameters compared CON and HEMI in right tibia (p < 0.05). Tb.Th and Tb.Sp distributions were differed CON with HEMI in right tibia. In left tibia, there were significant differences in RV of BMD (p < 0.05) and Tb.Sp distribution. These result means that SNI can induce bone loss in the both side tibiae. However, there was a different profile of bone loss between left and right tibiae.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.41 no.6
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• pp.73-80
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• 2004

In this paper, we propose a medical image processing method for detection of periodontal disease. The proposed method is the method of an automatic image alignment and detection of minute changes, to overcome defects in the conventional subtraction radiography by digital image processing technique, that is necessary for getting subtraction image and ROI(Region of Interest) focused on a selection method using the structured features in target images. And the method services accuracy, consistency and objective information or data to results. In result, easily and visually we can identify minute differences in the affected parts whether they have problems or not, and using application system.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.2
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• pp.161-169
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• 2012

Recently, a study for the functional surface production of super hydrophobic of natural and biomimetic artificial has attracted much attention. To make process methods of super hydrophobic surface has a variety of ways such as lithography, etching, and laser ablation. However, we were used ultra-shot pulse laser ablation process which has the virtue of more environmental friendliness and simple process. In this paper, we were fabricated a multiplicity of super hydrophobic patterns on mold surface(NAK80) using by optimizing the laser processing conditions and it was transferred on PDMS. Also, we measured contact angle super hydrophobic patterns on PDMS. The result showed there is no patterns on PDMS were measured 94 degrees, by contrast, optimized super hydrophobic patterns on PDMS was 157 degrees. Therefore we fabricated super hydrophobic surface on mold. Based on these experimental results, it is possible to mass production using ultra shot pulse laser ablation of super hydrophobic pattern and to be applied for a variety of industries.

• Journal of Veterinary Clinics
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• v.29 no.3
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• pp.263-267
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• 2012

A 4-year-old female Labrador Retriever dog was evaluated for a mass located in the left maxilla. Skull radiographic and CT findings revealed a soft tissue mass with bone lysis in the region of the left maxilla. Mass resection and surgical curettage was performed, and the mass was histopathologically classified as an acanthomatous ameloblastoma with a fibrous dysplasia.