• Journal of Periodontal and Implant Science
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• v.37 no.2
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• pp.151-164
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• 2007

Objective: The sinus floor elevation procedures have been used to facilitate implant placement in the severely atrophic posterior maxilla. Many variables may have an influence on the outcomes of the sinus floor elevation in combination with implant treatment. The aim of this study was to analyze survival rate of implants placed in the edentulous maxillae of patients in whom sinus floor elevation was undertaken according to variables. Materials and Methods: It consisted of 96 patients(50 male and 46 female), ranging in age from 31 to 70 years(mean 49 years), who underwent sinus floor elevation procedure(94 implants in left side and 106 implants in right side) from 2001 to 2002. A total of 200 implants were placed in the grafted sinus(73 implants in lateral approach and 127 implants in crestal approach). All implants were restored by fixed prosthesis. All patients were healthy. Follow-up periods for implants were between 48 to 60 months. Results: The cumulative survival rate of implants was 91.5%. Gender, age and operation site did not have an influence on the survival rate. There was statistically significant differences for the implants which placed in less than 4 or 5 rom residual bone height, the survival rate was 60%, 81.4% respectively (p<0.05). There was no statistically significant difference of implants survival rate ac- cording to approach technique. The survival rate for 100% autogenous bone grafts was lower with respect to composite grafts containing autogenous bone and 100% substitutes. The survival rate for hydroxyapatite-coated implants was statistically significant lower than other textured group (p<0.05). Conclusion: Residual bone height, surface texture and graft materials have an influence on the survival rate. To use autogenous bone as a part of a composite bone replacement, implant texture which leads to more favorable implant-bone interface were necessary. To determine residual bone height for initial implant stability was important.

• Journal of applied mathematics & informatics
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• v.26 no.1_2
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• pp.45-60
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• 2008

Here we consider the evaluation of the the dynamic component of the second order force due to wave diffraction by a circular cylinder analytically and numerically. The cylinder is fixed, vertical, surface piercing in water of finite uniform depth. The formulation of the wave-structure interaction is based on the assumption of a homogeneous, ideal, incompressible, and inviscid fluid. The nonlinearity in the wave-structure interaction problem arises from the free surface boundary conditions, namely, dynamic and kinematic free surface boundary conditions. We expand the velocity potential and free surface elevation functions in terms of a small parameter and then consider the second order diffraction problem. After deriving the pressure using Bernoulli's equation, we obtain the analytical expression for the dynamic component of the second order force on the cylinder by integrating the pressure over the wetted surface. The computation of the dynamic force component requires only the first order velocity potential. Numerical results for the dynamic force component are presented.

• Korean Journal of Remote Sensing
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• v.28 no.5
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• pp.549-559
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• 2012

This paper presents a comparative analysis on the applicability of a priori statistic information about adjustment models when the surface shape parameters are estimated at an arbitrary point in an elevation data. Although the reliability of the estimates are known to be affected by surface condition and the adjustment models, there has been little research in a systematic and detail way. When the raw data have been taken from a real measurement, its true value cannot be known, however, thus this study used simulation data in order to analyze clearly the applicability of adjustment models. The generation of simulated data was performed by superimposing horizontal, slope, and curve surfaces and adding a certain amount of noise. Comparative analysis was performed by associating the a posteriori estimates with a priori statistics of each adjustment models. The experimental results show the estimation characteristics of adjustment models against varying surface conditions.

• Journal of Dental Rehabilitation and Applied Science
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• v.24 no.4
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• pp.381-388
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• 2008

Various techniques and diversely designed implants have been developed to overcome anatomic limitations of the maxillary posterior alveolar bone. The OSFE (osteotome sinus floor elevation) technique has been used for maxillary sinus augmentation. Also, $Endopore^{(R)}$ implant was designed to increase the surface area by its sintered porous surface. The purpose of this study was to evaluate the survival rate of $Endopore^{(R)}$ implants placed in the posterior maxilla in association with the elevation of the sinus membrane using OSFE technique, and examine the new bone formation in the sinus. One hundred fifteen $Endopore^{(R)}$ implants in 66 patients were placed in the posterior maxilla by OSFE technique. The implants were clinically and radiographically followed up for an average of 26.3 months. Most implants were stable and radiographs showed that the bone regenerated in contact with the implants. But, 5 implants in 4 patients were removed after the prosthetic restoration and the survival rate was 95.6% during the follow-up period. The height of new bone formed in the sinus was $3.26{\pm}1.04mm$.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.04a
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• pp.309-312
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• 2004

In mountainous area with high relief, topography may cause cast shadows due to the blocking of direct solar radiation. Remote sensing images of these landscapes display reduced values of reflectance for shadowed areas compared to non-shadowed areas with similar surface cover characteristics. A variety of approaches are possible, though a common step in various active approaches is first to delineate the shadows using automated algorithm and digital surface model (or digital elevation model). This articles demonstrates a common confusion caused by cast shadows

• International Journal of Naval Architecture and Ocean Engineering
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• v.2 no.4
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• pp.195-199
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• 2010

This paper addresses the problem of B-spline surface interpolation of scattered points for a hull form design, which are not arbitrarily scattered, but can be arranged in a series of contours permitting variable number of points in the contours. A new approach that allows different parameter value for each point on the same contour has been adopted. The usefulness and quality of the interpolation has been demonstrated with some experimental results.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2011.05a
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• pp.204-204
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• 2011

최근 자동차수명의 연장, 고품질, 내식내마모성 향상의 요구에 따라 아연도금 및 합금도금의 친환경화, 아연합금도금특성 향상, 흑색화 실현, 아연-철, 아연-니켈 벤딩성 향상, 주석-아연 합금도금과 무전해 Ni-W-P, Ni-B-W, 전해 NiSiC-PTFE, Ni-Diamond복합도금 등의 도금현장 적용과 도금 후 3가 크로메이트 도장 밀착성에 대한 품질기술지원이 요구되고 있다.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2011.05a
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• pp.201-201
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• 2011

크롬대체도금으로 개발 추진되고 있는 전기Ni-W합금도금피막은 경질크롬 도금피막보다도 고온에서 경도 및 내 산성이 우수하고, 유리성형용 금형으로 사용되고 있다. 최근 일본에서는 지금까지의 무전해Ni-W-P합금피막에 비해서 텅스텐, 인의 함유율이 높고, 질산 이외의 염산, 황산의 산성 환경과 암모니아, 수산화나트륨 등의 알칼리성 환경에서도 부식이나 변색이 생기지 않는 무전해Ni-W-P합금도금기술을 크롬도금을 대체하는 도금으로서 개발하고 있다.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2012.05a
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• pp.288-289
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• 2012

이동통신, 전자부품의 고속송신에 따라 핵심으로 사용되는 인쇄회로기판(PCB, Printed Circuit Board)의 신뢰성을 향상시키기 위한 주석도금기술과 품질 향상이 요구되고 있다. 오랜 역사를 갖고 있는 습식전자부품 주석도금기술은 과거의 현장에서 기본원리, 도금액분석 등을 이수하는 정도였다. 최근 도금뿌리산업육성과 함께 PCB주석도금 신기술정보를 입수하여 현장품질기술지원이 필요하다. 이에 수시로 업그레이드되고 변화하고 있는 해외신기술동향과 특허정보를 지원하였다.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 1992.08a
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• pp.69-71
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• 1992

The local horizintal flux of tidal energy is characterized by the surface density $\omega$ = $\rho$ g h ζ u ($\rho$ - sea water density, g - gravitation, h - depth, ζ - tidal surface elevation, u - vertically averaged tidal current velocity vector). In general the flux vector $\omega$ comprises active and reactive components whose relation determines the local structure of a tidal wave.(omitted)