• Journal of the Computational Structural Engineering Institute of Korea
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• v.20 no.4
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• pp.493-499
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• 2007

The Taylor expansion expresses a differentiable function and its coefficients provide good approximations for the given function and its derivatives. In this study, m-th order Taylor Polynomial is constructed and the coefficients are computed by the Moving Least Squares method. The coefficients are applied to the governing partial differential equation for solid problems including crack problems. The discrete system of difference equations are set up based on the concept of point collocation. The developed method effectively overcomes the shortcomings of the finite difference method which is dependent of the grid structure and has no approximation function, and the Galerkin-based meshfree method which involves time-consuming integration of weak form and differentiation of the shape function and cumbersome treatment of essential boundary.

• The Research Journal of the Costume Culture
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• v.23 no.2
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• pp.294-309
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• 2015

This study aims to clarify the aesthetic values between emotion of human and expression of technology in contemporary fashion as it analyzes formative characteristics of related cases in fashion based on principles of 3D Printing technology and the viewpoint of mechanic aesthetics. The conclusions of this study are as follows. First, 3D Printing fashion is not only expressed diverse variations by its principles of formative methods, materials and properties, but also changes of silhouette by applying system of designers. Second, general characteristics of 3D Printing fashion is represented by various applications in SLS system, and it can be specifically explained application to a portion of clothing, decorative roles of clothing, complicated pattern making through crossing fabrics using 3D scanner and displaying a certain object changing fashion styles, and so forth. Third, the formative characteristics of 3D Printing fashion from the perspective of mechanic aesthetics is as follows. It can be analyzed as the integration of metaphysical values through compared symbolization of natural feature and technical evolution, partial dynamics and interactive velocity-based, formative combinations for abstract expression using architectural components, cosmos images and substantialized structures through images of organic space interacted human shapes. As the mention above, 3D Printing technology can creative a diverse area of fashion, and express images of new technological fashion through various works with continuous development of techniques.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.214.2-214.2
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• 2013

Device performance for the 45 and 32 nm node CMOS technology requires the integration of ultralow-k materials. To lower the dielectric constant for PECVD and spin-on materials, partial replacement of the solid network with air (k=1.01) appears to be more intuitive and direct option. This can be achieved introducting of second "labile" phase during depositoin that is removed during a subsequent UV curing and annealing step. Besides, with shrinking line dimensions the resistivity of barrier films cannot meet the International Technology Roadmap for Semiconductors (ITRS) requirements. To solve this issue self-forming diffusion barriers have drawn attention for great potential technique in meeting all ITRS requirments. In this present work, we report a Cu-V alloy as a materials for the self-forming barrier process. And we investigated diffusion barrier properties of self-formed layer on low-k dielectrics with or without UV curing treatment. Cu alloy films were directly deposited onto low-k dielectrics by co-sputtering, followed by annealing at various temperatures. X-ray diffraction revealed Cu (111), Cu (200) and Cu (220) peaks for both of Cu alloys. The self-formed layers were investigated by transmission electron microscopy. In order to compare barrier properties between V-based interlayer on low-k dielectric with UV curing and interlayer on low-k dielectric without UV curing, thermal stability was measured with various heat treatment temperature. X-ray photoelectron spectroscopy analysis showed that chemical compositions of self-formed layer. The compositions of the V based self-formed barriers after annealing were strongly dominated by the O concentration in the dielectric layers.

• Advances in aircraft and spacecraft science
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• v.8 no.4
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• pp.345-372
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• 2021

The analysis of nonlinear vibrations, buckling, post-buckling, flutter boundary determination and post-flutter behavior of a homogeneous curved plate assuming cylindrical bending is conducted in this article. Other assumptions include simply-supported boundary conditions, supersonic aerodynamic flow at the top of the plate, constant pressure conditions below the plate, non-viscous flow model (using first- and third-order piston theory), nonlinear structural model with large deformations, and application of mechanical and thermal loads on the curved plate. The analysis is performed with constant environmental indicators (flow density, heat, Reynolds number and Mach number). The material properties (i.e., coefficient of thermal expansion and modulus of elasticity) are temperature-dependent. The equations are derived using the principle of virtual displacement. Furthermore, based on the definitions of virtual work, the potential and kinetic energy of the final relations in the integral form, and the governing nonlinear differential equations are obtained after fractional integration. This problem is solved using two approaches. The frequency analysis and flutter are studied in the first approach by transferring the handle of ordinary differential equations to the state space, calculating the system Jacobin matrix and analyzing the eigenvalue to determine the instability conditions. The second approach discusses the nonlinear frequency analysis and nonlinear flutter using the semi-analytical solution of governing differential equations based on the weighted residual method. The partial differential equations are converted to ordinary differential equations, after which they are solved based on the Runge-Kutta fourth- and fifth-order methods. The comparison between the results of frequency and flutter analysis of curved plate is linearly and nonlinearly performed for the first time. The results show that the plate curvature has a profound impact on the instability boundary of the plate under supersonic aerodynamic loading. The flutter boundary decreases with growing thermal load and increases with growing curvature.

• Journal of the Korean Institute of Landscape Architecture
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• v.40 no.5
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• pp.51-62
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• 2012

Geumho-dong, Seoul, a redeveloped residential area, is located in the foothills of Mt. Eungbong. The geographical undulation, the composition of a large apartment complex, and the partial implementation of the redevelopment project have caused the severe physical and social disconnections in this area. In order to recover functioning in the disconnected community, this study pays attention to the regeneration of the open spaces as an everyday place and in the form a network system among those open spaces. Various types of the open spaces are classified into points or faces, 'bases' and linear 'paths' analyze the network status. More than half of the open space have connecting-distance of 500m or more. Furthermore, many areas are not even included in the service-area of the open spaces. Analysis of the connectivity and integration value using the axial map has carried out to check weak linkages and to choose the sections where additional bases are required. In addition, to improve the quality of the bases and the paths, a field investigation is conducted and problems are diagnosed. The network planning of the open spaces in Geumho-dong is established, ensuring the quality and quantity of bases and paths. The plan includes the construction of an additional major base in the central area and six secondary bases in other parts, and comes up with ways to improve the environment of underdeveloped secondary bases. In the neighborhood parks at Mt. Daehyun areas, the major path are added, and the environment of the paths is improved in certain areas. Because of the network planning, the connecting-distances between bases are reduced significantly, the connectivity and integration value of the area are increased, and the service areas of the open spaces cover the whole area properly. Although this study has some limitations such as the needs for the legal and institutional supports and difficulties of a quantitative indexing process, its significance lies in the suggestion of a more reasonable and practical plan for the overall network system by defining complex types of open spaces simply and clearly and by examining the organic relationships quantitatively and qualitatively.

• Smart Structures and Systems
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• v.3 no.3
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• pp.281-298
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• 2007

The load carrying capacity of a bridge needs to be properly assessed to operate the bridge safely and maintain it efficiently. For the evaluation of load carrying capacity considering the current state of a bridge, static and quasi-static loading tests with weight-controlled heavy trucks have been conventionally utilized. In these tests, the deflection (or strain) of the structural members loaded by the controlled vehicles are measured and analyzed. Using the measured data, deflection (or strain) correction factor and impact correction factor are calculated. These correction factors are used in the enhancement of the load carrying capacity of a bridge, reflecting the real state of a bridge. However, full or partial control of the traffic during the tests and difficulties during the installment of displacement transducers or strain gauges may cause not only inconvenience to the traffic but also the increase of the logistics cost and time. To overcome these difficulties, an alternative method is proposed using an excited response part of full measured ambient acceleration data by ordinary traffic on a bridge without traffic control. Based on the modal properties extracted from the ambient vibration data, the initial finite element (FE) model of a bridge can be updated to represent the current real state of a bridge. Using the updated FE model, the deflection of a bridge akin to the real value can be easily obtained without measuring the real deflection. Impact factors are obtained from pseudo-deflection, which is obtained by double-integration of the acceleration data with removal of the linear components on the acceleration data. For validation, a series of tests were carried out on a steel plategirder bridge of an expressway in Korea in four different seasons, and the evaluated load carrying capacities of the bridge by the proposed method are compared with the result obtained by the conventional load test method.

• Journal of the Korea Society of Computer and Information
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• v.17 no.10
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• pp.117-127
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• 2012

Identifying user requirements efficiently and reflecting them on the existing system is very important in a rapidly changing web and mobile environments. This study proposes the strategies to refining requirements and to prioritizing those refined requirements for changing of web and mobile application based on user requirements (e.g. mobile application comments, Q&A, reported information as discomfort factors). In order to refining the user requirements, those requirements are grouped by using the advancement of the software business of the Forum of standardization and the existing configuration-based programs. Then, we mapped them onto the PIECES framework to identifying whether the refined requirements are correctly reflected to the system in a way of valid and pure. To determine the priority of refined requirements, first, relative weights are given to software structure, requirements and categories of PIECES. Second, integration points on each requirement are counted to obtain the relative value of partial and overall score of a set of software structural requirements. In order to verifying the possibility and proving the effectiveness of proposing technique in this study, survey was conducted on changing requirements of mobile application which have been serviced at S University by targeting 15 people of work-related stakeholders.

• Proceedings of the Korean Society for Bioinformatics Conference
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• 2000.11a
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• pp.21-22
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• 2000

Expressed sequence tags (EFTs) are the partial segments of cDNA produced from 5 or 3 single-pass sequencing of cDNA clones, error-prone and generated in highly redundant sets. Advancement and expansion of Genomics made biologists to generate huge amount of ESTs from variety of organisms-human, microorganisms as well as plants, and the cumulated number of ESTs is over 5.3 million, As the EST data being accumulate more rapidly, it becomes bigger that the needs of the EST analysis tools for extraction of biological meaning from EST data. Among the several needs of EST analyses, the extraction of protein sequence or functional motifs from ESTs are important for the identification of their function in vivo. To accomplish that purpose the precise and accurate identification of the region where the coding sequences (CDSs) is a crucial problem to solve primarily, and it will be helpful to extract and detect of genuine CD5s and protein motifs from EST collections. Although several public tools are available for EST analysis, there is not any one to accomplish the object. Furthermore, they are not targeted to the plant ESTs but human or microorganism. Thus, to correspond the urgent needs of collaborators deals with plant ESTs and to establish the analysis system to be used as general-purpose public software we constructed the pipelined-EST analysis system by integration of public software components. The software we used are as follows - Phred/Cross-match for the quality control and vector screening, NCBI Blast for the similarity searching, ICATools for the EST clustering, Phrap for EST contig assembly, and BLOCKS/Prosite for protein motif searching. The sample data set used for the construction and verification of this system was 1,386 ESTs from human intrathymic T-cells that verified using UniGene and Nr database of NCBI. The approach for the extraction of CDSs from sample data set was carried out by comparison between sample data and protein sequences/motif database, determining matched protein sequences/motifs that agree with our defined parameters, and extracting the regions that shows similarities. In recent future, in addition to these components, it is supposed to be also integrated into our system and served that the software for the peptide mass spectrometry fingerprint analysis, one of the proteomics fields. This pipelined-EST analysis system will extend our knowledge on the plant ESTs and proteins by identification of unknown-genes.

• Journal of Periodontal and Implant Science
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• v.32 no.3
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• pp.539-554
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• 2002

It has been approximately 40 years since $Br{{\aa}}nemark$ first introduced osseo-integration for implants in the early 1960s. Unlike crown and bridge or denture treatment, implant treatment helps preserve existing bone and improve masticatory functions. Thus, the awareness of implant treatment has grown rapidly among dentists and patients alike in Korea, as it becomes a widely accepted treatment. The following results on patients type and implant distribution were compiled from 1814 implant cases of 640 patients treated at the periodontal dept. of Y University Hospital during 1992 to 2001. 1. There are no dissimilarities between men and women, with patients in their 40,50s accounting for 49% of patients and 56% of implant treatments; the largest share of patients and implant treatments. 2. Mn. posterior area accounted for 59% of implant treatments followed by Mx. posterior area(21%), Mx anterior area(l4%) and Mn anterior area 2%. 3. Partial edentulous patients treated by single crown and bridge-type prosthesis accounted for 98% and fully edentulous patient accounted for the remaining 2% 4. The major cause of tooth loss is periodontal disease, followed by dental caries, trauma and congenital missing. Compared to women, men are more likely to suffer from tooth loss due to periodontal disease. Also, older people are more likely to suffer from tooth loss due to periodontal disease rather than dental caries. 5. The distribution of bone quality for maxillae was 52% for type III, followed by 23% for type II, 20% for type IV and 0% for type I. As for mandible, the distribution was 52% for type II, followed by 37% for type III, 7% for type IV and 4% for type I. 6. The distribution of bone quantity for maxillae was 49% for type C, followed by 34% for type B, 14% for type D, 3% for type A, and 0% for type E. As for mandible, the distribution was 52% for type B, followed by 35% for type C, 6% for type D, 3% for type A and 0% for type E. 7. The majority of implants were those of 10-14mm in length (80%) and regular diameter in width (79%). The results provided us with basic data on patient type, implant distribution, bone condition, etc. We wish that our results coupled with other research data helps assist in the further study for better implant success/survival rates, etc.

• Archives of design research
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• v.15 no.1
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• pp.309-318
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• 2002

An expression of image in visual communication design traditionally has a dose relationship with the mechanical part of several expression media. Especially, an image conversion becomes easter by converging various forms of image such as a pictorial expression, a drawing up a plan, an optical expression and a reflected image into digital data in the image expression using digital mode. In addition, synthesis between various forms of visual ,images is activated by the integration of all expression media into digital mode and thus the extent of the image expression becomes diversified. Moreover, there is a tendency that a various dimensional expression such as 3D and 4D is generalized in the image expression of digital design. A partial or whole image conversion has often occurred during the generalization process of several image forms. Such conversion summarized into two factors, a formative side and a technical side. We described the existing pictorial expression as a formative side, an optical expression as a photography, a materialization of image conversion theory of computer graphic image conversion according to data form as a technical side and specific content according to dimension. We summarized objective and demonstrative resets through a simple simulation using a computer for the contents required a technical and qualitative measure and presented an application program of the particular results from the study to the visual communication design work by a case.