• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.5
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• pp.617-626
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• 2022

In Korea, annual precipitation and its variability have gradually increased since modern meteorological observations began, and the risk of disasters has also been increasing due to significant regional variations and recent abnormal climate conditions. Given that damage from storms and floods mainly occurs around rivers, it is crucial to determine the appropriate design frequency for river-related projects. This study examined existing design practices used to determine hydrological design frequencies and suggested a new method to determine appropriate design frequencies. The study collected available data pertaining to seven evaluation factors, specifically the basin areas, shape parameters, channel slopes, stream orders, backwater effect reaches, extreme rainfall frequencies, and urbanized flood inundation areasfor 413 local rivers in Chungcheongnam-do in Korea. The estimated weights for areas of extreme rainfall frequencies and urbanized flood inundation were found to be 18, having a great effect on determining the design frequency. Compared with the established design frequency in previous government reports, the estimated design frequency increased for 255 rivers and decreased for 158 rivers.

• Journal of Korean Tunnelling and Underground Space Association
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• v.2 no.3
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• pp.47-57
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• 2000

It is difficult to calculate factor of safety of a tunnel by applying any analytical method based upon limit equilibrium method since the shape of failure plane in tunnel analysis can not be easily assumed in advance. To cope with this shortcoming, a method is suggested to calculate safety factor of a tunnel by numerical analysis using strength reduction technique. A circular tunnel excavated in a homogeneous rock was selected as an example problem and factors of safety were calculated for no-supported, partly-supported, and completely-supported cases respectively. Meshes with 3 different sizes were examined for a sensitivity analysis. For the verification of the proposed method, a limit equilibrium analysis was conducted and compared with the numerical analysis. The proposed method herein can be used to calculate factor of safety of a tunnel regardless of tunnel shape or geological conditions, and thus can contribute for the improved design and stability assessment of tunnels.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.1 s.94
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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.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2010.04a
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• pp.512-515
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• 2010

본 논문에서는 등기하 해석법을 이용하여 설계의존형 하중조건을 갖는 구조물에 대한 형상 최적설계를 수행하였다. 유한요소법 기반 형상 최적설계는 CAD 모델과 해석 모델의 차이로 인해, 설계영역 매개변수화에 어려움이 있다. 등기하 해석법은 CAD 모델과 동일한 NURBS 기저 함수와 조정점을 해석에 이용함으로써 설계의 기하학적 변화를 해석모델에 직접적으로 표현할 수 있는 장점을 가진다. 하중조건이 설계 영역이 변화함에 따라 변하는 최적설계 문제의 경우, 정확한 설계 영역 표현은 법선 벡터, 즉 변화하는 하중의 방향과 곡률과 같은 고차항의 정보를 정확하게 표현할 수 있고, 따라서 목적함수를 최소 또는 최대화시키는 최적의 해로 이끌어 낸다. 유한요소법 또는 밀도법을 이용한 형상 최적설계에서 설계의존형 하중조건을 갖는 구조물의 문제를 푸는 경우, 최적설계가 진행됨에 있어 변화하는 경계의 부정확성 때문에 정확한 설계민감도를 얻기가 어려운 점이 있다. 본 논문에서는, 수치 예제를 통해 등기하 해석 기반의 형상 최적설계 방법론이 설계의존형 하중조건을 갖는 구조물 문제에서 수월성을 가짐을 확인하였다.

• Fashion & Textile Research Journal
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• v.18 no.6
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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.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.34 no.4
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• pp.255-262
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• 2021

In this study, a jointless bridge that integrates the superstructure and abutment without installing an expansion joint was analyzed. An example of a jointless bridge that has been introduced in Korea since 2009. Owing to the short period of use and lack of experience in design, construction, and maintenance, there is insufficient information regarding the long-term behavior of jointless bridges. When analyzing numerous bridges, the numerical analysis model must maintain the numerical values used and ensure the convenience of model construction. In this study, sensitivity analysis was performed to select a numerical model for various types of jointless bridges using commercial finite element programs, MIDAS Civil and ABAQUS 2018. According to a solid element-based model, we analyzed the mean and maximum relative errors between structural models. Consequently, it was found that the beam element-based model exhibits a significantly small relative error in comparison to the shell element, where a relatively large error was recorded. Therefore, the optimal numerical analysis model, a practical model that maintains the similarity and precision of the displacement shape cause by relative error, was judged to be the most suitable for jointless bridges based on the shell element.

• Fashion & Textile Research Journal
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• v.19 no.2
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• pp.121-133
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• 2017

This study investigates the design relation between shoulder line and sleeve line for designing bulky silhouettes as well as examines the trend sensitivity and design difference of each city through a comparison of the four cities collection (Paris, Milan, London, and New York). The results are as follows. In the four major fashion capitals, the rates of all-season coats were higher in 2014/15 F/W than those in the 2013/14 F/W season. At the 2014/15 F/W season, the proportion of the bulky silhouette coat, (including the fur and cape coat) increased and confirmed the bulky silhouette fashion trend. Second, an examining of the proportion of bulky silhouette coats manufactured by leading brands in major cities, indicated that London brands readily followed the trend of bulky silhouette coats when compared to other cities. This trend was also accepted by most brands in New York. Most brands in London and New York are highly compliant with the latest fashion trends. Third, the drop shoulder design was mostly presented in the shoulder pit of the bulky coat. In case of the sleeve, the shape of the jar was kept wide at the elbow line and made narrower toward the beak in most bulky silhouette coats. The importance of shoulder and sleeve design is clearly highlighted in the bulky silhouette coat. Fourth, detail design trends were different according to type of sleeve and shoulder fit. The results show the relationship between shoulder and sleeve design.

• Journal of Sensor Science and Technology
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• v.33 no.3
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• pp.173-178
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• 2024

Development of pressure sensors for harsh environments with high pressure, humidity, and temperature is essential for many applications in the aerospace, marine, and automobile industries. However, existing materials such as polymers, adhesives, and semiconductors are not suitable for these conditions and require materials that are less sensitive to the external environment. This study proposed a pressure sensor that could withstand harsh environments and had high durability and precision. The sensor comprised a piezoresistor pattern and an insulating film directly formed on a stainless-steel membrane. To achieve the highest sensitivity, a pattern design method was proposed that considered the stress distribution in a circular membrane using finite element analysis. The manufacturing process involved depositing and etching a dielectric insulating film and metal piezoresistive material, resulting in a device with high linearity and slight hysteresis in the range of a maximum of 40 atm. The simplicity and effectiveness of this sensor render it a promising candidate for various applications in extreme environments.

• The Research Journal of the Costume Culture
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• v.28 no.4
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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.

• Nuclear Engineering and Technology
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• v.19 no.2
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• pp.85-98
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• 1987

To analyze the aerosol dynamics in severe accidents of LMFBR, a new computer code entitled MCAD (Multicomponent Aerosol Dynamics) has been developed. The code can treat two component aerosol system using relative collision probability of each particles as sequences of accident scenarios. Coagulation and removal mechanisms incorporating Brownian diffusion and gravitational sedimentation are included in this model. In order to see the effect of particle geometry, the code makes use of the concept of density correction factor and shape factors. The code is verified using the experimental result of NSPP-300 series and compared to other code. At present, it fits the result of experiment well and agrees to the existing code. The input variables included are very uncertain. Hence, it requires uncertainty and sensitivity analysis as a supplement to code development. In this analysis, 14 variables are selected to analyze. The input variables are compounded by experimental design method and Latin hypercube sampling. Their results are applied to Response surface method to see the degree of regression. The stepwise regression method gives an insight to which variables are significant as time elapse and their reasonable ranges. Using Monte Carlo Method to the regression model of LHS, the confidence level of the results of MCAD and their variables is improved.