• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.1
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• pp.46-52
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• 2009

The maxillary posterior edentulous region presents unique and challenging conditions in implant dentistry. The height of the posterior maxilla is reduced greatly as a result of dual resorption from the crest of the ridge and pneumatization of the maxillary sinus after the loss of teeth. Materials previously used for sinus floor grafting include autogenous bone, allogeneic bone, xenogenic bone and alloplastic materials. Autogenous bone is the material of choice, but its use is limited by donor-site morbidity, complications, sparse availability, uncontrolled resorption and marked volume loss. One way to overcome this problem would be to use bone substitutes alone as a osteoconductive scaffold for bone regeneration from the residual bone or in combination with allogeneic bone, which also has osteoinductive properties. The purpose of this article is to describe a double layers technique of demineralized and mineralized bone graft materials instead of autogenous bone in sinus floor augmentation of deficient posterior maxillary alveolar process and to report our experience with this technique. Our results show that maxillary sinus augmentation using mineralized and demineralized bone materials, when installed simultaneously with the implant or not, is good results for bone healing.

• Biomaterials and Biomechanics in Bioengineering
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• v.3 no.1
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• pp.1-14
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• 2016

Well-ordered porous materials are very promising in orthopedics since they allow tailoring the mechanical properties. Finite element (FE) analysis is commonly used to evaluate the mechanical behavior of well-ordered porous materials. However, FE results generally differ importantly from experimental data. In the present article, three types of manufacturing irregularities were characterized on an additive manufactured porous titanium sample having a simple cubic unit-cell: strut diameter variation, strut inclination and fractured struts. These were included in a beam FE model. Results were compared with experimental data in terms of the apparent elastic modulus (Eap) and apparent yield strength (SY,ap). The combination of manufacturing irregularities that yielded the closest results to experimental data was determined. The idealized FE model resulted in an Eap one order of magnitude larger than experimental data and a SY,ap almost twice the experimental values. The strut inclination and fractured struts showed the strongest effects on Eap and SY,ap, respectively. Combining the three manufacturing irregularities produced the closest results to experimental data. The model also performed well when applied to samples having different structural dimensions. We recommend including the three proposed manufacturing irregularities in the FE models to predict the mechanical behavior of such porous structures.

• Communications of Mathematical Education
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• v.23 no.1
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• pp.39-51
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• 2009

The purpose of this article is to study characteristics of tangram as instructional media in combinatorialgeometric point of view, and to present basic materials and direction for efficient tangram activities in gifted education upon systematical analysis of methods of finding solutions. We can apply x=a+2b+4c to find all possible combination of solutions in tangram activities not as trial-and-error method but as analytical method. Through teacher's questions and problem posing in activities using tangram, we systematically came up with most solution and case of all possible combinations be solution in classifying properties of pieces and combining selected pieces.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.468-470
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• 1999

One of the most critical problem in etching of platinum was generally known that the etch slope was gradual. therefore, the addition of $N_2$ gas into the Ar/C1$_2$ gas mixture, which has been proposed the optimized etching gas combination for etching of platinum in our previous article, was performed. The selectivity of platinum film to oxide film as an etch mask increased with the addition of N2 gas, and the steeper etch slope over 75 $^{\circ}$ could be obtained. These phenomena were interpreted the results the results of a blocking layer such as Si-N or Si-O-N on the oxide mask. Compostional analysis was carried out by X-ray photoelectron spectroscopy (XPS) and secondary ion mass spectrometry (SIMS). Moreover, it could be obtained the higher etch rate of Pt film and steeper profile without residues such as p.-Cl and Pt-Pt ant the addition N\ulcorner of 20 % gas in Ar(90)/Cl$_2$(10) Plasma. The Plasma characteristic was extracted from optical emissionspectroscopy (OES).

• Proceedings of the KIEE Conference
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• 2008.11b
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• pp.157-159
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• 2008

This paper summarizes the results of these efforts by offering a photovoltaic system structure in 50kW. The combination of photovoltaic system components are interconnected and system monitoring system will be summarized for the purpose of the increasing safety in this article. This paper describes configuration of utility interactive photovoltaic system which generated electric power supplies to dormitory. In order to installing the middle or large scale photovoltaic system, It must investigated the optimal design of system, compute quantity of power generation, economic rate of return and so on. In this paper represent 50kW utility photovoltaic system examination, developed simulation results and financial analysis. The performance of photovoltaic system has been evaluated, analyzed with simulation and financial analysis results. The results obtained in this research will be much useful to prior investigation for installing utility interactive photovoltaic system.

• Communications of the Korean Mathematical Society
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• v.16 no.4
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• pp.679-690
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• 2001

Doubly stochastic matrices are n$\times$n nonnegative ma-trices whose row and column sums are all 1. Convex polytope $\Omega$$_{n}$ of doubly stochastic matrices and more generally (R,S), so called transportation polytopes, are important since they form the domains for the transportation problems. A theorem by Birkhoff classifies the extremal matrices of , $\Omega$$_{n}$ and extremal matrices of transporta-tion polytopes (R,S) were all classified combinatorially. In this article, we consider signed version of $\Omega$$_{n}$ and (R.S), obtain signed Birkhoff theorem; we define a new class of convex polytopes (R,S), calculate their dimensions, and classify their extremal matrices, Moreover, we suggest an algorithm to express a matrix in (R,S) as a convex combination of txtremal matrices. We also give an example that a polytope of signed matrices is used as a domain for a decision problem. In this context of finite reflection(Coxeter) group theory, our generalization may also be considered as a generalization from type $A_{*}$ n/ to type B$_{n}$ D$_{n}$. n/.

• Advances in robotics research
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• v.1 no.1
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• pp.101-126
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• 2014

In this article we present modular neural control for a leg-wheel hybrid robot consisting of three legs with omnidirectional wheels. This neural control has four main modules having their functional origin in biological neural systems. A minimal recurrent control (MRC) module is for sensory signal processing and state memorization. Its outputs drive two front wheels while the rear wheel is controlled through a velocity regulating network (VRN) module. In parallel, a neural oscillator network module serves as a central pattern generator (CPG) controls leg movements for sidestepping. Stepping directions are achieved by a phase switching network (PSN) module. The combination of these modules generates various locomotion patterns and a reactive obstacle avoidance behavior. The behavior is driven by sensor inputs, to which additional neural preprocessing networks are applied. The complete neural circuitry is developed and tested using a physics simulation environment. This study verifies that the neural modules can serve a general purpose regardless of the robot's specific embodiment. We also believe that our neural modules can be important components for locomotion generation in other complex robotic systems or they can serve as useful modules for other module-based neural control applications.

• International Journal of Computer Science & Network Security
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• v.21 no.8
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• pp.276-280
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• 2021

The article presents the concept of ICT - competence, which is considered as the most important characteristic of professional competence, which includes a combination of the following components: motivational-value (orientation of the individual to the development of his ITC-competence in future professional activities); technological (complex of skills and abilities of ICT activities); cognitive (a system of knowledge of modern technologies of future professional activity); it is determined that the pedagogical support of the formation of ICT competence of future specialists is the individualization of the process training, due to their personal and professional needs and the specifics of a regional university, providing the necessary conditions for the implementation of this process.

• Journal of Korea Multimedia Society
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• v.24 no.1
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• pp.155-165
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• 2021

With the continuous development and progress of science and technology, the field of mixed reality applications has involved scientific research, medicine, entertainment, education, information dissemination, and people's daily lives; This paper will focus on the application of mixed reality in the field of education and teaching, relying on the characteristics of mixed reality technology. This article will use the combination of mixed reality and smart glasses to fully consider the characteristics of photography darkroom teaching, design and produce a mixed reality photography darkroom teaching software, and explore the feasibility of the application of mixed reality in teaching. This paper will use literature research methods, practical research methods, and survey methods as the main methods of research topics to determine the importance, feasibility, and necessity of the relevant theories studied in this paper. The application of mixed reality technology in photography darkroom teaching can not only solve many problems in the existing darkroom teaching methods, but also develop and expand students' Independent learning ability. It is concluded from this that mixed reality teaching software has the feasibility of sustainable development, which brings particular application value to the development and research of other education and art discipline software.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.3
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• pp.947-971
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• 2022

The Electronic Medical Record (EMR) is a valuable source of medical data intelligence in e-health systems. The watermarking techniques have been used to authenticate the owner and protect the EMR from illegal copying. The existing distributive strategies, successfully operated to secure the EMR, are found to be inadequate. Blockchain technology, mainly, is employed by a sharing database that allows the digital crypto-currency. It rapidly leads to the magnified expectations acme. In this excitement, the use of consortium adopting the technology based on Blockchain, in the EMR structure, is found improving. This type of consortium adds an immutable share with a translucent record of the entire business and it is accomplished with responsibility, along with faith and transparency. The combination of watermarking and Blockchain technology provides a singular chance to promote a secured, trustworthy electronic documents administration to share with the e-records system. The authors, in this article, present their views on consortium Blockchain technology which is incorporated in the EMR system. The ledger, used for the distribution of the block structure, has team healthcare models based on dissimilar multiple image watermarking techniques.