• The Journal of Advanced Prosthodontics
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• 제12권6호
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• pp.351-360
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• 2020

PURPOSE. The aim of the present study was to compare the stress distributions on the dental implants, abutments, and bone caused by different overdenture attachment types under functional chewing forces. MATERIALS AND METHODS. The 3D finite element models of the mandible, dental implants, attachment types, and prostheses were prepared. In accordance with a conventional dental implant supported overdenture design, the dental implants were positioned at the bone level in the canine teeth region bilaterally. A total of eight models using eight different attachment systems were used in this study. All the models were loaded to simulate chewing forces generated during the centric relationship (450 N), lateral movement (400 N), protrusive movement (400 N), and also in the presence of a food mass unilaterally (200 N). Stress outputs were obtained as the maximum principal stress and the equivalent von-Mises stress. RESULTS. In all attachment types, higher stress values were observed in the abutments, dental implants, and bone in the magnet attachments in different loading conditions. The highest stress values were observed among the magnet systems in the components of the Titanmagnetics model in all loading conditions (stresses were 15.4, 17.7, and 33.1 MPa on abutment, dental implant, and bone, respectively). The lowest stress value was observed in the models of Zest and O-Ring attachments. CONCLUSION. The results of the present study implied that attachment types permitting rotation and tolerating various angles created lower stresses on the bone, dental implants, and abutments.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제47권2호
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• pp.76-81
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• 2021

Objectives: We aimed to collect and report data from all patients who have been diagnosed with mucosal malignant melanoma to obtain the epidemiology and principles of current treatments. Materials and Methods: Between January 2008 and December 2018, 20 patients underwent surgery or follow-up observations at Yonsei University Dental Hospital. The patients' clinical information was reviewed retrospectively. Results: Seventeen of 20 patients had undergone definitive surgery, while only 6 patients received adjuvant radiotherapy or systemic therapy. Eight of 20 patients, including those that had recurrent lesions, were provided immunotherapy. The 3-year survival for all stages was 50%, with a local recurrence rate of 75% and a metastasis rate of 65%. Conclusion: The overall survival of patients receiving surgical treatment was longer than that of patients who did not undergo surgical resection. Eight of 20 patients received immunotherapy as the first-line regimen at our clinic, and those patients exhibited longer overall survival compared to patients in reported keynote studies.

• 한국실내디자인학회논문집
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• 제17호
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• pp.109-119
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• 1998

This study investigates the characteristics of Mario Botta's single-family houses. Eight of his housing project which are deemed important in the historical development of housing he been selected for the purpose their elevations plans loggie and interiors are analyzed and evaluated. Through this study the followings are realized ; $\circled1$ The rationality of his interior space comes from Le Corbusier's housing projects. $\circled2 His expression of elevations has developed from Louis. I. Kahn's language and Carlo Scarpa's technique. $\circled3$ The rationality of Corbusier's houses and expressiveness of Kahn's and scarpa's projects together led to his functional solution of internal program an and the creative external images of his own. $\circled4$ The originality of this house results from his creative vision and ability to reinterpret the existing expression and principles in the light of time and space.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.253-257
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• 2003

This paper presents the Development of Switching Power Supply for testing communication equipment. The communication equipment need many kinds of voltage(-48V,27V,12V,5V,3.3V), and in case of low voltage needs large current($10{\sim}20A$). The previous Linear Power Supply was very heavy, has low efficiency and poor power-factor for testing communication equipment. This development has good efficiency and high power-factor using switch mode power supply technique. This Development of Switching Power Supply is composed of eight converters. The principles of operation, feature, and design considerations are illustrated and verified through the experiment with 600W prototype.

• 대한수학교육학회지:학교수학
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• 제3권2호
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• pp.373-399
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• 2001

The function is a basic and key concept to understand mathematical problems. However, many students have difficulties to expand the knowledge to other related concepts and to transfer the knowledge to real world problems. The reasons for the problem may be that the concept of function is taught by simplified and abstracted formula without fully understanding of the reasoning process. Also, the examples for the concepts are artificial and not related to students' experiences. Situated learning theory provides great implications to solve these problems. So, this study was designed to teach the concept of function more meaningful to students by appling situated learning theory. Thirty-eight middle school students were participated in this study. Students were provided the instruction designed according to the principles of situated learning theory. Then, they were asked to complete attitude survey questionnair and a performance assessment task. The result showed that the instruction based on situated learning theory was useful to Promote students' understanding and motivation for learning. More implications of the study was provided in the paper.

• 대한한의진단학회지
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• 제19권2호
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• pp.109-113
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• 2015

Byunzheng(辨證), 'Identification of Patterns' implies the process of identifying the original cause from symptoms and signs. Each symptom and sign has a meaning that manifests. But in Clinic, it is difficult to recognize the main cause through symptoms and signs by itself, because the patients complaint their symptoms differently. When considering Byunzheng, not only one symptom of one cause but relationship of manifested symptoms and causes are necessary. The object of Byunzheng is to diagnose Illness and disease through symptoms and signs and to coordinate Therapeutic Methods by Byunzheng. In Byunzheng, there are patterns according to the function of Internal Organs(臟腑), the Channels, the Eight Principles, the Five Elements and etc. Process to Diagnose Byunzheng is the most important. Until present, it is not clear to conclude the Byunzheng process or criteria. In certain case of Byunzheng is recognized by doctor's intuition, but most case is needed for conscious reasoning. Therefore, in this statement, process of conclude Byunzheng is reviewed rather than describing each character of Byunzheng.

• Archives of Pharmacal Research
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• 제17권5호
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• pp.348-353
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• 1994

The activity fractionation upon the MeOH extract of the root of trichosanthes kirilowii led to the isolation of eight cucurbitane tritepense namely cucurbitacin .betha. (I), isocucurbitacin .betha.(II), cucurbitacin D(III), isocucurbitacin D(IV), 3-epi-isocucurbitacin .betha(V), dihydrocucurbitain .betha. (VI), dihydroisocucurgbitachin .betha. (VII) and dihydrocucurbitacin E (VIII), as active principles. All isolates were shown to exhibit significant cytotoxicity against cultured human tumor cells, including A-549, Sk-OV-3, Sk-MEL-2, XF-498 and HCT 15, with an exceptionally high potency.

• 농촌계획
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• 제15권4호
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• pp.147-160
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• 2009

In 1977, the Main Street Program(MSP) of the United States was founded by the National Trust for Historic Preservation to revitalize downtowns which suffered major declines in their economy and population. This study analyzed the methodology of MSP such as the Four-Point Approach and the Eight Principles, history of MSP, local program organizational structure, local program budgets and funding, official designation and so on. Three successful cases were discussed the background of an introduction to MSP, implementations, results and revitalization statistics. To be able to apply rural development projects in Korea, this study showed the implications such as the need for a program's ethic and methodology, a strong public-private partnership, a dedicated organization, a full-time professional program manager, a commitment to good design and comprehensive work plan, and an educational program of ongoing training for staff, volunteers and other residents.

• 생약학회지
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• 제27권3호
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• pp.238-245
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• 1996

The activity guided fractionation of $CH_2Cl_2$ soluble part of Platycarya strobilacea leaves(Juglandaceae) has led to the isolation of eight active principles, identified as 5-hydroxy-2-methoxy-1,4-naphthoquinone(1), ursolic acid(2), gallic acid(3), 4,8-dihydroxynaphthalene $1-O-{\beta}-_D-glucoside(4)$, eriodictyol(5), quercetin $3-O-(2'-O-galloyl)-{\beta}-_D-glucoside(6)$. quercetin $3-O-(2'-O-galloyl)-{\beta}-_D-galactoside(7)$ and quercetin $3-O-{\alpha}-_L-rhamnoside(8)$ by the means of chemical and spectral evidence, respectively.

• 대한기계학회논문집A
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• 제28권11호
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• pp.1646-1655
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• 2004

A description of the basic principles of moire interferometry leads to the design of a eight-mirror four-beam interferometer for obtaining fringe patterns representing contour-maps of in-Plane displacements. The technique is implemented by the optical system using an environmental chamber for submicro-displacement mesurement. In order to estimate the reliability and applicabili쇼 of the system developed, the measurement of coefficient of thermal expansion (CTE) for a aluminium block is performed. Consequently, the system is applied to the measurement of thermal deformation of a WB-PBGA package assembly. Temperature dependent analyses of global and local deformations are presented to study the effect of the mismatch of CTE between materials composed of the package assemblies. Bending displacements of the packages and average strains of solder balls are documented. Thermal induced displacements calculated by FEM agree quantitatively with experimental results.