• 제목/요약/키워드: Irregularity

검색결과 847건 처리시간 0.03초

The Derailment Safety Estimation of DMT Freight for Real Track Condition (실제 선로조건에 따른 DMT 화차의 탈선안전도 평가)

  • Lee, Jong-Seong;Eom, Beom-Gyu;Lee, Seung-Il;Lee, Hi-Sung
    • Proceedings of the KSR Conference
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    • 한국철도학회 2011년도 춘계학술대회 논문집
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    • pp.830-835
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    • 2011
  • DMT Freight is judged that economic performance is good because can increase cargoes than existing freight. However, the existing freight cars, each with a different balance to the body structure is bogie because the vibrations may occur. Thus, by minimizing vibration over the existing freight securing the safety of the driving if you will not have major problems in cargoes. In this study, multi-body dynamic analysis tool, VI-Rail using the actually Gyeongbu Railroad line and an empty, full freight condition include curve radius, track irregularity, cent. DMT freight of the derailed wagons were assessed for safety analysis. Full and empty freight conditions for parity in the Gyeongbu Railroad line(Dongdaegoo ${\leftrightarrow}$Gyungsan) derailment safety analysis, such as derailment safety coefficient and the radius wheel road decrement, echoing the curve and the orbit is affected by the irregularity was found. Full freight condition than the empty conditions showed a significant derailment safety. Overall, the limits of derailment coefficient (Q/P=0.8) and wheel road decrement limits (${\Delta}P/P=0.6$) is less safe with me confirmed that the derailment safety.

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A Semantic Analysis of the Indeterminacy in Contemporary Fashion - Focusing on Fashion Since 2000 - (현대 패션에 나타난 불확정성의 의미해석 - 2000년대 이후 패션을 중심으로 -)

  • Hwang, Hye-Jin;Kim, Min-Ja
    • Journal of the Korean Society of Costume
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    • 제62권5호
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    • pp.1-15
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    • 2012
  • In a fast changing postmodern society, contemporary fashion is becoming more complicated and ambiguous along with other genres of art than ever before. This phenomenon reigning as a sociocultural paradigm can be defined as 'indeterminacy' and it means 'undecidability'. The purpose of this study is to clarify and analyze the indeterminate characteristics of contemporary fashion reviewing the theoretical background and the architectural formativeness as a comparative research. The core idea of deconstructivism dismantles a causal relationship between function and form in fashion and the conventional notion about clothes. Complexity theory, which is the study of chaotic dynamical systems, suggests the creative idea and concept of infinite possibilities on a formative method. Meanwhile, catastrophe theory of discontinuous change can be used as interpretative strategies for the process of deconstruction and reconstruction. As a result of this study, the indeterminacy of fashion can be analyzed into five semantic categories: irregularity, immateriality, randomness, complexity and changeability. The intrinsic value of the indeterminacy in contemporary fashion is the interaction with a sociocultural ideology and a technological environment as well as an expansion of formative expression. To conclude, it can be said that the indeterminacy in fashion is a new interpretation of the relationship among body and space, clothes and society.

Seismic Damage to RC Low-rise Building Structures Having Irregularities at the Ground Story During the 15 November 2017 Pohang, Korea, Earthquake (2017.11.15. 포항 흥해지진의 저층 RC 비틀림 비정형 건축물의 피해 및 손상 특성)

  • Hwang, Kyung Ran;Lee, Han Seon
    • Journal of the Earthquake Engineering Society of Korea
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    • 제22권3호
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    • pp.103-111
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    • 2018
  • This study examines the seismic failure of RC low-rise building structures having irregularities at the ground story during the 15 November 2017 Pohang, Korea, earthquake, $M_w=5.4$, which is the second strongest since the government began monitoring them in 1978 in South Korea. Some 2,000 private houses were damaged or destroyed in this earthquake. Particularly, serious damage to the piloti story of RC low-rise residential building structures of fewer than five stories was observed within 3 km of the epicenter with brittle shear failure of columns and walls due to severe torsional behavior. Buildings below six stories constructed before 2005 did not have to comply with seismic design requirements, so confinement detailing of columns and walls also led to inadequate performance. However, some buildings constructed after 2005 were damaged at the flexible side of the piloti story due to the high torsional irregularity. Based on these results, this study focuses on the problems of the seismic torsion design approach in current building codes.

Prediction of Rolling Noise of a Korean High-Speed Train Using FEM and BEM (유한요소법과 경계요소법을 이용한 한국형 고속전철의 전동소음 예측)

  • 양윤석;김관주
    • Journal of KSNVE
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    • 제10권3호
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    • pp.444-450
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    • 2000
  • Wheel-rail noise is normally classified into three catagories : rolling impact and squeal noise. In this paper rolling noise caused by the irregularity between a wheel and a rail is analysed as follows: The irregularity between the wheel and the rail is assumed as linear superposition of sinusoidal profiles. Wheel-rail contact stiffness is linearized by using Hertzian contact theory and then contact force between the wheel and the rail is calculated. vibration of the rail and the wheel is calculated theoretically by receptance method or FEM depending on the geometry of the wheel or the rail for the frequency range of 100-500 Hz important for noise generation. The radiation noise caused by those vibration response is computed by BEM To verify this analysis tools rolling noise is calculated by proposed analysis steps using typical roughness data and these results are compared with experimental rolling noise data. This analysis tools show reasonable results and finally used for the prediction of the Korean high speed train rolling noise.

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Measurements of scattering and absorption coefficients of diffusers with variation of surface area (확산체의 표면적 변화에 따른 흡음 및 확산계수 측정)

  • Kumar P., Senthil;Kim, Yong-Hee;Jeon, Jin-Yong
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 한국소음진동공학회 2007년도 추계학술대회논문집
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    • pp.983-986
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    • 2007
  • The absorption power of a surface depends on the surface irregularity which has been known as an important factor in determining scattering coefficient. This study investigates the effect of increase in surface area on the absorption and scattering coefficients of a diffuse surface. The surface irregularity or surface pattern can be compared to the wavelengths and the random-incidence scattering coefficient of surface is measured by ISO 17497-1. The scattering coefficients of increasing the surface area in linear pattern of v-cut groove on rubber plate were measured in 1:10 scale model reverberation chamber. It is found that the scattering and absorption coefficients increase with increasing surface area. At 60% of increased surface area the spacing between the hemisphere diffuser and the v-cut groove acts similar with results of absorption coefficient. The results show that absorption coefficient depends on surface area and the spacing where as scattering coefficient depends on surface area and texture.

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Development of an Automated Design System for Oil Pumps with Multiple Profiles(Circle, Ellipse and Involute) (원, 타원 및 인벌루트 조합된 치형형상을 갖는 로터 개발)

  • Jung, Sung-Yuen;Kim, Moon-Saeng;Cho, Hae-Yong;Kim, Chul
    • Journal of the Korean Society for Precision Engineering
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    • 제26권3호
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    • pp.103-112
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    • 2009
  • A internal lobe pump is suitable for oil hydraulics of machine tools, automotive engines, compressors, constructions and other various applications. In particular, the pump is an essential machine element of an automotive engine to feed lubricant oil. The subject of this paper is the theoretical analysis of internal lobe pump whose the main components are the rotors: usually the outer one is characterized by lobe with elliptical and involute shapes, while the inner rotor profile is determined as conjugate to the other. And the integrated system which is composed of three main modules has been developed through AutoLISP under AutoCAD circumstance. It generates new lobe profile and calculates automatically the flow rate and flow rate irregularity according to the lobe profile generated. Results obtained from the analysis enable the designer and manufacturer of oil pump to be more efficient in this field.

Parametric analysis on Deformation of Sharp Curved Ballasted Track (급곡선 자갈궤도의 궤도변형에 관한 매개변수 해석)

  • Choi, Jung-Youl;Kim, Jun-Hyung;Son, Gab-Soo;Kim, Sang-Jin
    • Journal of the Korean Society of Safety
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    • 제32권4호
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    • pp.28-33
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    • 2017
  • A sharp curved ballasted track on earthwork that was connected with a direct fixation slab track on steel box railway bridges have been deformed and damaged despite the frequently maintenance by a restoring force of sharp curved rail and track-bridge interaction forces such as axial forces and longitudinal displacement of continuous welded rail(CWR) owing to their structural characteristics, calling for alternatives to improve the structural safety and track irregularity. In this study, the authors aim to prove a cause of deformation for the sharp curved ballasted tracks to enhance the structural safety and track irregularity of ballasted track in service. A track-bridge interaction analysis and a finite-element method analysis for the sharp curved ballasted track were performed to consider the axial force and longitudinal displacement of CWR, the temperature and the effect of restoring force of sharp curved rail. From the results, the deformation of the sharp curved ballasted track with adjusted sleeper spacing from 833mm to 590mm were significantly reduced.

Displacement-based seismic design of open ground storey buildings

  • Varughese, Jiji Anna;Menon, Devdas;Prasad, A. Meher
    • Structural Engineering and Mechanics
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    • 제54권1호
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    • pp.19-33
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    • 2015
  • Open ground storey (OGS) buildings are characterized by the sudden reduction of stiffness in the ground storey with respect to the upper infilled storeys. During earthquakes, this vertical irregularity may result in accumulated damage in the ground storey members of OGS buildings without much damage in the upper storeys. Hence, the structural design of OGS buildings needs special attention. The present study suggests a modification of existing displacement-based design (DBD) procedure by proposing a new lateral load distribution. The increased demands of ground storey members of OGS buildings are estimated based on non-linear time history analysis results of four sets of bare and OGS frames having four to ten storey heights. The relationship between the increased demand and the relative stiffness of ground storey (with respect to upper storeys) is taken as the criterion for developing the expression for the design lateral load. It is also observed that under far-field earthquakes, there is a decrease in the ground storey drift of OGS frames as the height of the frame increases, whereas there is no such reduction when these frames are subjected to near-field earthquakes.

Shake-table responses of a low-rise RC building model having irregularities at first story

  • Lee, Han Seon;Jung, Dong Wook;Lee, Kyung Bo;Kim, Hee Cheul;Lee, Kihak
    • Structural Engineering and Mechanics
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    • 제40권4호
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    • pp.517-539
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    • 2011
  • This paper presents the seismic responses of a 1:5-scale five-story reinforced concrete building model, which represents a residential apartment building that has a high irregularity of weak story, soft story, and torsion simultaneously at the ground story. The model was subjected to a series of uni- and bi-directional earthquake simulation tests. Analysis of the test results leads to the following conclusions: (1) The model survived the table excitations simulating the design earthquake with the PGA of 0.187 g without any significant damages, though it was not designed against earthquakes; (2) The fundamental mode was the torsion mode. The second and third orthogonal translational modes acted independently while the torsion mode showed a strong correlation with the predominant translational mode; (3) After a significant excursion into inelastic behavior, this correlation disappeared and the maximum torsion and torsion deformation remained almost constant regardless of the intensity of the two orthogonal excitations; And, (4) the lateral resistance and stiffness of the critical columns and wall increased or decreased significantly with the large variation of acting axial forces caused by the high bi-directional overturning moments and rocking phenomena under the bi-directional excitations.

A Study on Readability Improvement Method for Ancient Inscription of Irregularity Surface using Cross Section Analysis (단면형상 분석을 이용한 요철이 심한 금석문(金石文) 판독 향상 방법 연구)

  • Choi, Won-Ho;Ko, Sun-Woo
    • Journal of Information Technology Services
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    • 제13권2호
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    • pp.251-259
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    • 2014
  • Outdoor cultural properties have been damaged by natural weathering and air pollution for a long time. For this reason, there are many characteristics it is hard to decipher some carved inscription on the surface of damaged outdoor cultural properties. Until now, Rubbed copy has been widely used to decode engraved inscription. A investigation for epigraph has been made by the rubbing that has resulted in a lower resolution from the viewpoints of extraction process and used materials. Rubbing's results are not satisfied in the damaged inscriptions which are weathered by natural environment and pollution for a long time and in the narrowed one. The main analysis presented in this paper is a cross section analysis method using 3d scanning technique for epigraph not read. Cross section analysis is a study on readability improvement method for ancient inscription of irregularity monument surface. Cross section analysis confirms information that separated the inscription information of monument and the ground information to read a ancient inscription and decode the inscription information. The proposed character identification method contributed to decoding an ancient inscription on Silla Monument in Jungseong-ri of Pohang.