• The Journal of Advanced Prosthodontics
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• 제14권3호
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• pp.182-202
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• 2022

PURPOSE. The aim of this study is to summarize various biomechanical aspects in evaluating the long-term stability of dental implants based on finite element method (FEM). MATERIALS AND METHODS. A comprehensive search was performed among published studies over the last 20 years in three databases; PubMed, Scopus, and Google Scholar. The studies are arranged in a comparative table based on their publication date. Also, the variety of modeling is shown in the form of graphs and tables. Various aspects of the studies conducted were discussed here. RESULTS. By reviewing the titles and abstracts, 9 main categories were extracted and discussed as follows: implant materials, the focus of the study on bone or implant as well as the interface area, type of loading, element shape, parts of the model, boundary conditions, failure criteria, statistical analysis, and experimental tests performed to validate the results. It was found that most of the studied articles contain a model of the jaw bone (cortical and cancellous bone). The material properties were generally derived from the literature. Approximately 43% of the studies attempted to examine the implant and surrounding bone simultaneously. Almost 42% of the studies performed experimental tests to validate the modeling. CONCLUSION. Based on the results of the studies reviewed, there is no "optimal" design guideline, but more reliable design of implant is possible. This review study can be a starting point for more detailed investigations of dental implant longevity.

• 복식문화연구
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• 제28권4호
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• pp.429-445
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• 2020

The purpose of this study is to provide ideas for the development of bag design by analyzing the expression types and aesthetic formativeness of modern bag design using tassels and fringe given the newtro trend pursuing analog sensitivity in modern society. The methods and scope of this study are as follows. First, the related literature and internet data were reviewed in order to examine the expression types and characteristics of the bags of the West and East. Next, the definition and characteristics of tassel and fringe decoration in terms of the history of clothing were analyzed. Finally, the expression types and aesthetic formativeness of tassels and fringe were derived through the analysis of modern bag design shown in the fashion collections since 2010. The bags decorated with the tassels and fringe bring a variety of visual effects depending on the attachment position, direction and material composition, concentrating the gaze and radiating original style. In this study, the expression of tassels and fringe in modern bag design was classified into three types: surface decoration, shape variability, and object combination. Next, the aesthetic formativeness of modern bag design using tassels and fringe as decorative elements appeared through the mixture of heterogeneous materials and playfulness through imagination, exaggeration through extension of length and volume, and retro characteristics through reinterpretation of tradition. This study is expected to contribute to creative ideas of modern bag design which requires a global sense, which has been used in various cultures for a long time.

• 대한인간공학회지
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• 제28권3호
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• pp.103-114
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• 2009

This study investigated perceived discomfort and reasons related to use three information technology products (personal computer, mobile phone and digital television remote controller), and extracted the universal design factors. 240 people (30 females and 30 males for four age groups) participated in the one-to-one interview type of questionnaire, and replied to degree of discomfort at level of items and the reasons of discomfort at level of detailed elements for each product. As a result, almost all age groups answered that using input buttons of mobile phone and remote controller and watching display of mobile phone caused discomfort. Binary logistic regression of the detailed elements showed that response rate of discomfort mostly increased with age, except for specific elements such as shape of mouse and remote controller, and location of function button of mobile phone. Some of the detailed elements had high response rate of discomfort from all age groups. The age groups also showed similar tendency for the elements to select one alternative for the reason of discomfort, but not for sound volume and size of mobile phone and button sensitivity of remote controller. Finally, the universal design factors were extracted for each product based on the results, and divided into common factors and factors classified by the age group. Through this study, we identified using practices of various age groups and their demands for the products. It is expected that extracted detailed elements can be considered as important design factors to design the products universally.

• 복식문화연구
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• 제24권5호
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• pp.642-652
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• 2016

The purpose of this study is to understand the concept of a sexual image and verify the method of its design expression through case studies of the sexual image evening dress shown in an Haute Couture Collection over the last 10 years (2005~2014). The results of analysis are as follows: First, "expression by the seeing through of the natural body" expressed a natural sexual image that combined fashion of the previous times with the beauty of the natural body by using a see-through material and classic or ethnic image. Second, "expression of a sexual-image look that emphasizes romantic detail" illustrated a romantic sexual image that emphasizes feminine sensitivity by mixing various ornamental elements such as see-through material and symbolism of underwear image. Third, "creation of a nude look using skin color" expressed sexual image of an evening dress by inducing erotic sexual association through a combination of opaque material of skin color and design shape that is intended for body exposure. Fourth, "combination of sexual symbol and heterogeneous elements" expressed a decadent, avant-garde and futuristic sexual images by using women's underwear and a sexual symbol as design motif and mixed with mismatching elements. Fifth, "use of a fantastic black image" expressed an exclusive and refined sexual image and a decadent and primitive sexual image by using a fantastic image of black color. The results of this study are expected to be used for the design process of the evening-dress industry that aims for quality improvement.

• 대한기계학회논문집A
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• 제21권5호
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• pp.707-718
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• 1997

This paper presents an efficient numerical method for the computation of eigenpair derivatives for a real symmetric eigenvalue problem with distinct and multiple eigenvalues. The method has a very simple algorithm and gives an exact solution. Furthermore, it saves computer sotrage and CPU time. The algorithm preserves not only the symmetricity but also the band width of the matrices, allowing efficient computer storage and solution techniques. Results from the proposed method for calculating the eigenpair derivatives are compared with those from Rudisill and Chu's method and Nelson's method which is known efficient one in the case of distinct natural frequencies. As an example to demonstrate the efficiency of the proposed method in the case of distinct eigenvalues, a cantilever plate is considered. The design parameter of the cantilever plate is its thickness. For the eigenvalue problem with multiple natural frequencies, the adjacent eigenvectors are used in the algebraic equation as side conditions, lying adjacent to the multiplicity of multiple natural frequency distinct eigenvalues, which appear when design parameter varies. A cantilever beam is used to demonstrate the efficiency of the proposed method in the case of multiple natural frequencies. Results form the proposed method for calculating the eigenpair derivatives are compared with those from Dailey's method(an amendation of Ojalvo's work) which finds the exact eigenvector derivatives. The design parameter of the cantilever beam is its height. Data is presented showing the amount of CPU time used to compute the first ten eigenpair derivatives by each method. It is important to note that the numerical stability of the proposed method is proved.

• 한국터널지하공간학회 논문집
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• 제2권3호
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• pp.47-57
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• 2000

터널의 파괴는 사면의 경우처럼 파괴면의 형상을 사전에 가정하기 어렵기 때문에 한계평형법에 기초한 해석법을 적용하여 안전율을 구하기가 곤란하다. 본 연구에서는 이러한 문제를 극복하기 위하여 강도감소기법을 이용한 수치해석기법에 의해 터널의 안전율을 구하는 방법을 제시하였다. 균질한 암반에 굴착된 원형터널을 가정하여 무보강, 부분보강 및 인버트의 완전한 폐합의 경우에 대하여 안전율을 계산하였으며, 요소망의 크기에 따른 민감도 분석을 위해 크기가 다른 3가지의 요소망을 사용하여 계산 결과를 비교하였다. 제안된 방법의 검증을 위해, 특정한 파괴 활동면을 갖는 경우에 대해 한계평형해석을 수행하여 수치해석 결과와 비교하였다. 본 논문에서 제안한 터널의 안전율 계산 방법은 터널의 형상이나 암반의 상태에 관계없이 적용될 수 있으므로 향후 터널 설계 및 안정성 평가에 큰 도움이 될 수 있을 것으로 생각된다.

• 한국의류산업학회지
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• 제18권6호
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• pp.787-799
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• 2016

This study considers aesthetic characteristics by examining fashion style of fashion journalist Anna Wintour. Fashion journalists are specialists who work at fashion media. Especially, Anna Wintour is one of the most famous fashion journalist in the world and fashion icon, who has been editor-in chief of Vogue USA since 1988. For this study, Anna Witour's photograph was collected from 2010 to 2015 on web-sites. After collecting images, it analysed with 4criterions which were silhouette, color, fabric(pattern and texture) and hair style(and accessories) following advance researches analysis about fashion style. The conclusions of this study are as follows. First, symbolism revealed that could express her identity through utilizing steady items such as blond bob hair, Chanel bold sunglasses, short round neckless and Manolo Blahnik's low-heeled slingback nude sandals. Especially, she gave consistency to her fashion style with fixed hair style and accessories which are similar in shape. Second, femininity, that reveal as an internal characteristic such as sensitivity and as an external characteristic like fluidity. Anna Wintour expressed femininity with elegant curvy silhouette, various of color and flower pattern. Particularly, she emphasized nature women's body shape with princess silhouette, slim silhouette. Third, analysis result indicated characteristic of authority with oversize silhouette, wide lapel details and glamorous genuine fur items. Furthermore, some of her fur items looked overwhelming which dyed in artificial color or printed with leopard pattern. These powerful items contained immanent meanings that are power and position which could express a role as an editor-in chief of Vogue USA.

• 한국소음진동공학회논문집
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• 제15권1호
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• pp.72-80
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• 2005

Recent studies have dealt with brake squeal in terms of the coupled vibration of brake component parts. In this paper, we assemble the mode models derived from FE analysis of the individual components of the drum brake system into the system model by considering the friction interaction of the lining and drum at the interface. The validity of the component models are backed up by the experimental confirmation work. By scrutinizing the real parts of the complex eigen-values of the system, the unstable modes, which may be strong candidate sources of squeal noise, are identified. Mode participation factors are calculated to examine the modal coupling mechanism. The model predictions for the unstable frequencies pointed well the actual squeal noise frequencies measured through field test. Sensitivity analysis is also performed to identify parametric dependency trend of the unstable modes, which would indicate the direction for the squeal noise reduction design. Finally, reduction of the squeal noise tendency through shape modification is tried.

• 한국해양공학회지
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• 제17권4호
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• pp.31-36
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• 2003

In case of this thick rolling-steel for a multistory building, a large oil-drilling structure, a large vessel, a bridge and so on, Lamella Tearing around the welded joint zone is the most serious problems. In order to prevent Lamella Tearing, not only is choice of material important, but also the comprehensive investigation for the structural design and the construction. The Lamella Tearing that is a staircase-shape occurs due to the contraction stress to the thickness direction of the plate and has the character that the cracks progress along the elongated inclusion by rolling. In general, because cracks occur at the heat affected zone and around HAZ, it is necessary to establish the safety and the confidence of the welded structure to restrain the welding defect such as Lamella Tearing. The mechanical approaches are the easier and more economical than the approaches of the material and the construction method. In addition, the appropriate welding profile and the optimum welding condition contribute toward the improvement of the productivity and influence on the standardization of the manufacturing technology.

• Structural Engineering and Mechanics
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• 제63권1호
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• pp.37-46
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• 2017

This paper is concerned with the numerical study on the resonance response of a rigid spar-type floating platform in coupled heave and pitch motion. Spar-type floating platforms, widely used for supporting the offshore structures, offer an economic advantage but those exhibit the dynamically high sensitivity to external excitations due to their shape at the same time. Hence, the investigation of their dynamic responses, particularly at resonance, is prerequisite for the design of spar-type floating platforms which secure the dynamic stability. Spar-type floating platform in 2-D surface wave is assumed to be a rigid body having 2-DOFs, and its coupled dynamic equations are analytically derived using the geometric and kinematic relations. The motion-variance of the metacentric height and the moment of inertia of floating platform are taken into consideration, and the hydrodynamic interaction between the wave and platform motions is reflected into the hydrodynamic force and moment and the frequency-dependent added masses. The coupled nonlinear equations governing the heave and pitch motions are solved by the RK4 method, and the frequency responses are obtained by the digital Fourier transform. Through the numerical experiments to the wave frequency, the resonance responses and the coupling in resonance between heave and pitch motions are investigated in time and frequency domains.