• Journal of the Korean Data and Information Science Society
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• 제25권6호
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• pp.1231-1239
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• 2014

In this paper we analyse the distributions of the number of goals scored by home teams and away teams in K-league soccer outcomes between 1983 and 2012. Real soccer data is explained in K-league using statistical distributions such that Poisson, negative binomial, extreme value and zero inflated Poisson. How close the goals of home and away fits the different distributions are tested by performing chi-square goodness of fit tests. According to these tests, the Poisson distribution gives the best fit to the home goals data. But it is best to model the away goals data on zero inflated Poisson distribution. Also, there is some weak evidence of the dependence for home and away goals.

• The Journal of the Korean bone and joint tumor society
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• 제1권1호
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• pp.38-44
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• 1995

Metastatic bone tumor is the most common bone tumor and 32.5% of all primary malignant tumors are eventually metastasize to bone. Metastatic bone tumor has been more frequently encountered disease in the orthopedic fields due to the greater longevity of life of the patients with primary visceral cancers by major advances in early detection, diagnosis, and surgical/radiotherapeutic/chemotherapeutic treatment of primary and metastatic lesions. Therefore, the epidemiologic data about the incidences and the patterns of bone metastasis is important. We reviewed 417 patients who were diagnosed and treated for metastatic bone tumor at Kosin University Medical Center from 1985 to 1993 to analyse the primary lesion, age and sex distributions, location of bone metastasis, patterns of metastasis according to the primary. The results were as follows : 1. The common origin of bone metastasis were lung(29.5%), stomach(15.3%), breast(11.3%), unknown(7.7%), cervix(5.3%), liver(4.8%) in order of frequency. 2. There were 251 men and 166 women and their mean age was 54.8 years and the peak age incidence was in 6th decades. Most cases(85.3%) were occured beyond 5th decades. 3. The preferred sites of metastatic deposits were spine(64.0%), pelvis(40.5%), rib(38.8%), femur(36.7%), skull(21.1%), humerus(13.9%), scapula(13.0%) in order of frequency. In the spine, thoracic(42.1%), lumbar(39.1%), cervical(13.2%), sacral(5.6%) vertebrae were involved in order of frequency. 4. Multiple bone metastases were more common(73.1%) than single metastasis(26.9%). 5. In the lung cancer, the peak age incidence was 6th decades, and the preferred sites of bone metastasis were spine, pelvis, femur. 6. In the stomach cancer, the peak age incidence was 6th decades, and the preferred sites of bone metastasis were spine, femur, pelvis. 7. In the breast cancer, the peak age incidence was 5th decades, and the preferred sites of bone metastasis were spine, rib, pelvis. 8. In the bone metastasis with unknown primary site, the peak age incidence was 7th decades, the preferred sites of bone metastasis were spine, femur, pelvis, and the common histologic types were adenocarcinoma and squamous cell carcinoma.

• The Journal of the Korea Contents Association
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• 제14권9호
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• pp.343-349
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• 2014

The dental osseointegration implant should be enough to endure occlusion load and it's required to have efficient design and use of implant to disperse the stress into bones properly. Solidworks as a finite element analysis program for modeling and analysis of stress distribution was used for the research. The simple crown model was designed on applying conjoined condition with tightening torque of 20 Ncm of a abutment screw between a cement retained implant abutment and a fixture. A $45^{\circ}$ oblique loading from lingual to buccal side on buccal cusps of crown and performed finite element analysis by 100 N of external load. The results by a analysis for stress distribution of supporting bones of fixture were as below. The von Mises stress was concentrated on the upper side of supporting compact bone regardless of the diameters and lengths of fixture, and the efficiency result of stress reduction was increase of fixture's diameter than it's length. Therefore, it's effective to use wider fixture as possible to the conditions of supporting jaw bone.

• The korean journal of orthodontics
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• 제33권1호
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• pp.11-20
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• 2003

The purpose of the present study is to evaluate the stress distribution on the length and diameter of the miniscrew and cortical bone width. Three dimensional finite element models were made of diameter 1.2mm, 1.6mm, 2.0mm and length 6.0mm, 8.0mm, 10.0mm, 12.0mm and cortical bone width 1.0mm. Also, another three dimensional finite element models were made of diameter 1.2mm, 1.6mm, 2.0mm and length 8.0mm and cortical bone width 1.0mm, 1.5mm, 2.0mm, 2.5mm. Two-hundred grams horizontal force were applied on the center of the miniscrew head and at that stress distribution and its magnitude had been analyzed by ANSYS, which is three dimensional finite element analysis program. The obtained results were as follows : 1. The comparison of the maximum von-Mises stress in the miniscrew showed that as the diameter increases from 1.2mm to 2.0mm stress has been decreased, while on the same diameter stress was not changed regardless of the length change. 2. The comparison of the maximum von-Mises stress in the cortical and cancellous bone showed that as the diameter increases from 1.2mm to 2.0mm stress has been decreased, while on the same diameter stress was not changed regardless of the length change. 3. In the analysis of the stress distribution in the cortical and cancellous bone, the most of the stress had been absorbed in the cortical bone, and did not transmitted much to the cancellous bone. 4. In the analysis of the maximum von-Mises stress according to the cortical bone width, the same diameter of the miniscrew showed a constant stress value regardless of the cortical bone width change. The above results suggest that the maintenance of the miniscrew is more reliable on diameter than length of the miniscrew.

• Food Engineering Progress
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• 제14권2호
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• pp.106-111
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• 2010

In this study, we performed corrugation fluting experiments to examine the relationship between high-low corrugation of a corrugated medium and compressive strength of corrugated containers for food packaging. A low-grade corrugated medium was found to suffer from weak tensile resistance and to be prone to stealing, which tends to produce low corrugation. In contrast, a medium with a large corrugation deviation often caused slimming during fluting and produced irregular corrugations. Experiments of high-low corrugation distribution according to corrugated medium grades indicate that a high grade medium shows a smaller ratio of low corrugation. The thickness of corrugated fiberboard is weakly correlated to the basis weight of medium, yet positively correlated to the medium thickness (y=3.9732x+4.2712, $R^{2}=0.8142$) and inversely proportional to the medium density (y=-3.1213x+6.8736, $R^{2}=0.9919$). Compressive strength of a corrugated fiberboard box is low, if made of corrugated medium with large low corrugation distribution. Compressive strength showed 13% variation with respect to medium grades and 21% variation for various test samples. The corrugation fluting of a corrugated medium is related to physical properties such as basis thickness and density.

• 대한치과보철학회:학술대회논문집
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• 대한치과보철학회 1997년도 추계학술대회
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• pp.25-25
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• 1997

• The Journal of Korean Academy of Prosthodontics
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• 제34권4호
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• pp.699-721
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• 1996

브로네마르크가 골유착성 임플랜트를 소개한 이래로, 현재 골유착성 임플랜트에 의한 치료는 안전하고 안정적인 방법으로 여겨지고 있다. 골유착성 임플랜트를 이용한 초기의 치료는 무치악 환자의 저작기능 회복에 중점을 두어 왔다. 그러나 현재는 환자와 시대의 요구에 따라서 심미성이 주요한 관심사가 되었다. 그래서 표준 지대주보다 더 심미적인 지대주 시스템들이 개발되었다. 다양한 직경의 임플랜트 고정체에 관한 임상가들의 요구에 의해 직경 이 큰 고정체가 생산되기 시작했으며, 5mm의 직경을 갖는 고정체가 그 예이다. 골유착성 임플랜트를 사용하여 보철치료를 할 때, 골과 고정체의 계면은 보철물과 지대주에 가해지는 교합력을 인접골에 전달하게 되며, 이것은 계면에 생물학적인 반응을 야기할 수 있다. 임플랜트의 형태는 골흡수와 같은 바람직하지 않은 반응을 일으키지 않도록 고안되어야 하며, 임플랜트 자체가 교합력을 견딜 수 있어야 한다. 그러므로 골유착성 임플랜트 시스템을 임상에 사용하려고 할 때 이것의 생역학적 분석은 반드시 필요하다. 본 연구에서는 삼차원 유한요소분석적 방법을 사용하여 3.75mm직경을 갖는 고정체에 표준 지대주, 이세티콘 지대주, 마이러스콘 지대주를 연결한 모델과 5mm 직경을 갖는 고정체에 표준 지대주를 연결한 모델에 각각 수직하중, 경사하중, 수평하중을 가했을 때의 응력분포를 비교하였다. 본 연구의 결과는 다음과 같다. 1. 모든 모델에서 금나사의 경부, 금원주, 지대주에 응력의 집중이 일어났다. 2. 임플랜트 고정체에서는 고정체 상방 2/3, 그리고 지대주와 접촉하는 고정체 상면에서 응력의 집중이 관찰되었다. 3. 골에서는 상부 피질골에 응력의 집중이 관찰되었으며, 해면골에서는 두드러진 응력의 집중을 보인 부위는 없었으나 고정체의 근단부 주위 해면골에서의 응력값이 비교적 높았다. 4. 5mm 직경의 고정체를 사용하지 않은 모델 중에서, 표준 지대주를 사용한 경우가 가장 응력분산에 유리하였으며 마이러스콘 지대주를 사용한 경우가 가장 불리하였다. 5. 3가지 하중 조건하에서 수평하중과 경사하중의 경우가 수직하중의 경우보다 더 높은 응력값이 관찰되었다. 6. 응력값은 골에서보다 임플랜트 내부에서 훨씬 높았다.

• Journal of Dental Rehabilitation and Applied Science
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• 제25권3호
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• pp.255-265
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• 2009

Recently many studies have been published on application of immediate loaded implants. However, the immediate loading protocol has not been well documented. The purpose of the present study was to evaluate the stress distribution between bone-implant interfaces and the effect of implant length in the anterior maxilla using 3 dimensional finite element analyses. The diameter 4.0 mm threaded type implants with different length(8.5 mm, 10.0 mm, 11.5 mm, 13.0 mm, 15.0 mm) were used in this study. The bone quality of anterior maxillary bone block was assumed to D3 bone. Bone-implant interfaces of immediately loaded implant were constructed using a contact element for simulating the non osseointegration status. For simplification of all the processing procedures, all of the material assumed to be homogenous, isotropic, and linearly elastic. The 178 N of static force was applied on the middle of the palatoincisal line angle of the abutment with $120^{\circ}$ angle to the long axis of abutment. Maximum von Mises stress were concentrated on the labial cortical bone of the implant neck area, especially at the cortical-cancellous bone interfaces. Compared the different length, highest peak stress value was observed at the 8.5 mm implants and the results indicated a tendency towards favorable stress distribution on the bone, when the length was increased. Presence of cortical bone was very important to immediate loading, and it appears that implants of a length more than 13 mm are preferable for immediate loading at the anterior maxilla.

• The Journal of Korean Academy of Prosthodontics
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• 제56권2호
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• pp.105-113
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• 2018

Purpose: The purpose of this study was to investigate the effects of the insertion depth of an immediately loaded implant on the stress distribution of the surrounding bone and the micromovement of the implant using the three-dimensional finite element analysis. Materials and methods: A total of five bone models were constructed such that the implant platform was positioned at the levels of 0.00 mm, 0.25 mm, 0.50 mm, 0.75 mm, and 1.00 mm depth from the crest of the cortical bone. A frictional coefficient of 0.3 and the insertion torque of 35 Ncm were simulated on the interface between the implant and surrounding bone. A static load of 178 N was applied to the provisional prosthesis with a vertical load in the axial direction and an oblique load at $30^{\circ}$ with respect to the central axis of the implant, then a finite element analysis was performed. Results: The implant insertion depth significantly affected the stress distribution on the surrounding bone. The largest micromovement value of the implant was $39.34{\mu}m$. The oblique load contributed significantly to the stress distribution and micromovement in comparison to the vertical load. Conclusion: Increasing the implant insertion depth was advantageous in dispersing the concentrated stress in the cortical bone and did not significantly affect the micromovement associated with early osseointegration failure.

• Journal of Dental Rehabilitation and Applied Science
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• 제25권2호
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• pp.109-123
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• 2009

The aim of the study was to assess the influence of insertion torque of bone quality and to compare axial force, moment and von Mises stress using finite element analysis of plastoelastic property for bone stress and strain by dividing bone quality to its thickness of cortical bone, density of trabecular bone and existence of lower cortical bone when implant inserted to mandibular premolar region. The $Br{\aa}nemark$ MKIII. RP implant and cylindrical bone finite model were designed as cortical bone at upper border and trabecular bone below the cortical bone. 7 models were made according to thickness of cortical bone, density of trabecular bone and bicortical anchorage and von Mises stress, axial force and moment were compared by running time. Dividing the insertion time, it seemed 300msec that inferior border of implant flange impinged the upper border of bone, 550msec that implant flange placed in middle of upper border and 800msec that superior border of implant flange was at the same level as bone surface. The maximum axial force peak was at about 500msec, and maximum moment peak was at about 800msec. The correlation of von Mises stress distribution was seen at both peak level. The following findings were appeared by the study which compared the axial force by its each area. The axial force was measured highest when $Br{\aa}nemark$ MKIII implant flange inserts the cortical bone. And maximal moment was measured highest after axial force suddenly decreased when the flange impinged at upper border and the concentration of von Mises stress distribution was at the same site. When implant was placed, the axial force and moment was measured high as the cortical bone got thicker and the force concentrated at the cortical bone site. The influence of density in trabecular bone to axial force was less when cortical bone was 1.5 mm thick but it might be more affected when the thickness was 0.5 mm. The total axial force with bicortical anchorage, was similar when upper border thickness was the same. But at the lower border the axial force of bicortical model was higher than that of monocortical model. Within the limitation of this FEA study, the insertion torque was most affected by the thickness of cortical bone when it was placed the $Br{\aa}nemark$ MKIII implant in premolar region of mandible.