• Title/Summary/Keyword: 구조적 붕괴

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A Study on the Plasticity of the Gather Represented in Haut Couture (최근 오뜨꾸뛰르 복식에 표현된 개더(Gather)의 조형성에 관한 연구)

  • 강숙녀
    • Archives of design research
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    • v.11 no.3
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    • pp.25-33
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    • 1998
  • A Study on the Plasticity of the Gather Represented in Haute Couture The Gather is the plastic technique to represent a sense of voluminosity by pleating the plane of costume and manifests the emotional effects , such as both functional aspects and the construction of form, optical illusion effect, textural feelings from materials, tactile transformations, etc. So it is used as the tool to represent the plastistic beauty of costume. The plasticity of the ancient gather was the drape arising according to the curve of the body, but the type of gather recently found on the haute couture does not only retain the activity and functionalism on which the technical element and the ornamental aspect are mixed with other techiques.

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Estimating the Term Structure of Interest Rates Using Mixture of Weighted Least Squares Support Vector Machines (가중 최소제곱 서포트벡터기계의 혼합모형을 이용한 수익률 기간구조 추정)

  • Nau, Sung-Kyun;Shim, Joo-Yong;Hwang, Chang-Ha
    • The Korean Journal of Applied Statistics
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    • v.21 no.1
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    • pp.159-168
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    • 2008
  • Since the term structure of interest rates (TSIR) has longitudinal data, we should consider as input variables both time left to maturity and time simultaneously to get a more useful and more efficient function estimation. However, since the resulting data set becomes very large, we need to develop a fast and reliable estimation method for large data set. Furthermore, it tends to overestimate TSIR because data are correlated. To solve these problems we propose a mixture of weighted least squares support vector machines. We recognize that the estimate is well smoothed and well explains effects of the third stock market crash in USA through applying the proposed method to the US Treasury bonds data.

A review of DEM resolution based on flood inundation analysis (DEM 해상도에 따른 홍수범람해석 검토)

  • Lim, Jae Deok;Park, Su Hee;Park, Chan Hee;Yoo, Sang Yeon
    • Proceedings of the Korea Water Resources Association Conference
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    • 2022.05a
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    • pp.223-223
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    • 2022
  • 최근 도시지역의 홍수피해가 증가함에 따라 홍수방어대책이 중요해지고 있다. 제방 축조 및 배수시설 개선 등의 구조적 대책이 우선되어야 하나, 계획빈도 이상의 호우로 인한 피해 발생시 인명피해 및 재산피해를 최소화하기 위한 비구조적 대책 또한 중요한 실정이다. 본 연구에서는 도시지역의 비구조적 대책 수립을 위해 하천 제방 붕괴로 인한 홍수범람 해석을 수행하였다. 도시지역의 홍수범람 해석은 일반적으로 확산형의 흐름 특성을 가져, 홍수의 잠재성이 크다고 판단되는 도시지역에 대해 확산형 범람 해석을 통해 홍수의 전파양상을 심층적으로 검토할 수 있는 Flumen 모형을 적용하였다. "홍수위험지도 작성에 관한 지침(2020, 환경부)"에서는 2차원(확산형) 홍수범람 분석시 LiDAR 기반 1m급 DEM 자료를 권장하고 있으나, 영산·섬진강권역(제주도 포함) 내 1m급 DEM 자료는 약 11,320km2가 구축되어 전체면적(17,756km2) 대비 64%만 구축되어 도시지역 전체 적용에 한계가 있다. 본 연구에서는 도시지역과 농경지가 포함된 도시지역(농촌형 도심지역)을 대상으로 1m급 DEM과 5m급 DEM을 구분하여 2차원(확산형) 홍수범람 분석을 수행하였다. 도시지역으로는 지방하천 순천동천이 관류하는 순천시가지를 선정하였고, 농촌형 도심지역으로는 지방하천 광치천이 관류하는 남원시가지를 선정하였다. 2차원 홍수범람 해석을 위해 주요 지점별 파제 시나리오는 각 지구별 동일하게 작성하였으며, DEM 자료에 따른 검토 결과, 도시지역의 경우 지하차도 등과 같은 시설로 인한 차이가 발생하였으나, 농촌형 도시지역의 경우 DEM 해상도에 따른 침수양상 및 면적 차이가 크지 않은 것으로 검토되어 농촌형 도시지역의 경우 5m급 DEM 자료의 활용이 가능한 것으로 검토되었다. 추후 전국 지방·도시하천에 대한 홍수위험지도 제작이 완료된다면 홍수로 인한 침수피해에 대해 사전에 대비하고, EAP, 재해지도 제작, 수해방지대책 수립 등 관련 계획수립 시 기초자료로 활용이 가능할 것이다.

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A Study on the Snap-through Behaviour of Plate Elements due to the Initial Deflection Shape (초기처짐형상에 따른 판부재의 천이거동에 관한 연구)

  • Park, Joo-Shin;Lee, Kye-Hee;Ko, Jae-Yong
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.18 no.1
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    • pp.13-20
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    • 2005
  • Since High Tensile Steel has been widely used to thin plate on the steel structure and marine structure, It has increased possibility of buckling. Especially, initial deflection of ship structure is mainly caused by heat processing of welding or cutting etc. This initial deflection has negative effect to thin plate, which would incur a complicated nonlinear behavior accompanied with secondary buckling. If idealized initial deflection is considered in early marine structure design of secondary buckling, accuracy and reliability will be improved considerably. The measurement data of initial deflection from experiment is applied to finite element series analysis. For FEA(ANSYS), Applied nonlinear buckling analysis is used by Newton-Raphson method & Arc-length method included in this program.

An Analysis of Network Structure in Housing Markets: the Case of Apartment Sales Markets in the Capital Region (주택시장의 네트워크 구조 분석: 수도권 아파트 매매시장의 사례)

  • Jeong, Jun Ho
    • Journal of the Economic Geographical Society of Korea
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    • v.17 no.2
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    • pp.280-295
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    • 2014
  • This paper analyzes the topological structure of housing market networks with an application of minimal spanning tree method into apartment sales markets in the Capital Region over the period 2003.7-2014.3. The characteristics of topological network structure gained from this application to some extent share with those found in equity markets, although there are some differences in their intensities and degrees, involving a hierarchical structure in networks, an existence of communities or modules in networks, a contagious diffusion of log-return rate across nodes over time, an existence of correlation breakdown due to the time-dependent structure of networks and so on. These findings could be partially attributed to the facts that apartments as a quasi-financial asset have been strongly overwhelmed by speculative motives over the period investigated and they can be regarded as a housing commodity with the highest level of liquidity in Korea.

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Evaluation of Roofing Potential at the Ground-structure Interface (지반-구조물 경계면의 루핑 포텐셜 평가)

  • Park, Jeongman;Kim, Kanghyun;Shin, Jongho
    • Journal of the Korean GEO-environmental Society
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    • v.19 no.3
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    • pp.25-33
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    • 2018
  • Piping is one of the most frequently occurring collapse type of a levee, and is often caused by roofing (backward erosion piping) at the ground-structure interface. Roofing is generally evaluated using creep ratio. However, creep ratio does not take into account the characteristics of the ground-structure interface. In this study, the roofing risk was investigated by using model test and numerical analysis considering the ground-structure interface characteristics. In the model test, it was confirmed that the piping potential decreased as the interface roughness increased, and this was applied to the numerical analysis. Existing numerical methods can not adequately simulate the particle behavior at the ground-structure interface because only the water level difference is considered. In this paper, particle behavior at the interface was investigated by performing seepage analysis and then, carrying out particle analysis technique simulating the boundary condition of the ground-structure interface. Analysis results have shown that the roofing resistance decreases as the ground-structure interface roughness decreases.

Effects of Explosion on Structures (폭발이 구조물에 미치는 영향)

  • Yoon, Yong-Kyun
    • Explosives and Blasting
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    • v.37 no.4
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    • pp.10-16
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    • 2019
  • Information on overpressure, positive phase duration, and impulse are required to assess the effects of shock waves or pressure waves on the structure. In this study, the overpressure and positive phase duration were determined by applying the Multi-Energy Method, which is found to be effective in analyzing the explosion of vapor clouds. Based on the total heat of combustion estimated in the cyclohexane vapor cloud explosion in the Nypro Ltd(UK), overpressure and positive phase duration at the distance of 40, 80, 120, 160, 200, 240, 280, 320, 360(m) from the source of explosion were evaluated. Overpressure was shown to decrease exponentially and positive phase duration increased almost linearly with distance. A probit function was used to assess the probability of damages for the structures at each distance using the overpressure and impact obtained at the above mentioned distances. The Analyses of probability of damages have shown that there is a high probability of collapse at distances within 120m, major damage to structures within 240m, and minor damage and breakage of window panes of structures occur over the entire distances.

Analysis of Structural and Thermal Parameters for Evaluating Fire Resistance of Steel Beams (철골보의 내화시간 평가를 위한 구조 및 열적 변수해석)

  • Park, Han Na;Ahn, Jae Kwon;Lee, Cheol Ho
    • Journal of Korean Society of Steel Construction
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    • v.21 no.6
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    • pp.609-618
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    • 2009
  • This paper proposes a versatile formula which can be used to evaluate the fire resistant time of steel beams under various design conditions. Towards this end, the key parameters which affect the fire performance of steel beams were first determined through thermo-mechanical considerations, and classified into two groups: structural parameters and thermal parameters. Then the degree of influence of each parameter on the fire performance was investigated through a fully coupled thermo-mechanical analysis up to the occurrence of run-away deflection. The accuracy of the numerical model used was verified using an available full-scale fire test before conducting an extensive parametric analysis. Multiple linear regression analysis was performed to obtain the formula which can be used to predict the fire resistance time of steel beams under various design conditions. The statistical analysis showed that the proposed formula is very robust. The application of the formula in practical fire design under the current code was illustrated in detail. The economy and other advantages of the proposed formula were clearly shown.

Fundamental Study on Developing Embedded Mini-Sensor for Nondestructive Diagnosis Corrosion of Rebar (비파괴 철근 부식 진단을 위한 매립형 미니센서 개발에 관한 기초적 연구)

  • Joh, Sung-Hyung;Lim, Young-Chul;Ismail, Mohamed;Lee, Han-Seung
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.14 no.6
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    • pp.179-187
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    • 2010
  • Corrosion of rebar embedded reinforced concrete is the main cause of collapse and degradation of reinforced concrete structure. Degradation occurs in reinforced concrete structures from corrosion caused by the Chloride that the damage other than the severe degradation of the structure in terms of maintenance and construction when the huge expense required and deciding terms is hard. Therefore, early detection of rebar corrosion is important for efficient maintenance and repairing and planning. Meanwhile, how to evaluate the corrosion of the non-destructive measurements have been used a lot. In particular CM-II (corrosion meter) is used to measurement the natural potential, polarization resistance and the resistivity of the concrete, but has some disadvantages. Embedded mini-sensor has been developed in order to overcome these disadvantages. So Measurement corrosion for using the mini-sensor compares with the measured results CM-II (corrosion meter), the developed mini-sensor verify the validity.

Synthesis of amorphous Fe-Cr-N alloy powders by mechanical alloying (기계적 합금화에 의한 Fe-Cr-N 계 비정질 합금분말의 제조)

  • 이충효
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.9 no.1
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    • pp.132-136
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    • 1999
  • Mechanical alloying (MA) by ball mill of $Fe_{30}Cr_{70}$ elemental powders was carried out under the nitrogen gas atmosphere. Amorphization has been observed in this case, while MA under an inert argon gas atmosphere produces the bcc solid solution. The DSC spectrum for the mechanically alloyed $(Fe_{30}Cr_{70})_{0.85}N_{0.15)$powders exhibits a sharp exothermic peak due to crystallization at about $550^{\circ}C$. Structural transformation from the bcc crystalline to amorphous states was observed through X-ray and neutron diffractions. During amorphization process the octahedral unit, which is typical of a polyhedron formed in any crystal structures, was preferentially destroyed and transformed into the tetrahedral unit. Futhermore, neutron diffraction measurements revealed that a nitrogen atom is situated at a center of the tetrahedron formed by metal atoms.

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