• Title/Summary/Keyword: geometric structure

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A Study on the Secondary Optimization Analysis based on the Result of Primary Structure Analysis for the Die Thickness (금형두께에 대한 1차 구조해석 결과를 기반으로 한 2차 최적화 해석에 관한 연구)

  • Lee, Jong-Bae;Kim, Sang-Hyun;Woo, Chang-Ki
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.6
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    • pp.3448-3454
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    • 2014
  • Generally existing structure analysis was applied to elastic analysis basically in practice. Considering the nonlinear material and the nonlinear geometric to be a more precise analysis, for this reason, The necessity for a structual analysis have been constantly required. Therefore, after optimization is performed, designed a simple model which is applied the principle of nonlinear in this study, a structural analysis of existing experienced users, have a aims at presenting theory and a method in order to perform anyone the analysis easily. In this study, the proposed model applied to die ribs, Regarding the shear load, less strain and stress was generated but strength was sufficient. The initial strain and stress was reconfigured to fit the size and shape, A hyperstudy in conjunction with Abaqus with nonlinear structural analysis, revealed an acceptable maximum and minimum range of stress and under the conditions of minimum strain, the plate made with a constant increment. In the experimental models, the plate thickness was given a power of 40 Newton, according to the thickness of the press die through an iterative process. When the stress and strain was applied to the die thickness, 7-8mm thickness could be obtained by optimizing.

The Development of Operating Standards for the Adjustment of Pedestrian Green Phasing at a Signalized Intersection (신호교차로에서 보행자신호 전시간 운영기준 설정을 위한 연구)

  • Lee Choul-Ki;Lee Seok;Shim Dae-Young;Kim Gyun-Jo
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.2 no.1 s.2
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    • pp.41-52
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    • 2003
  • The purpose of this study was to test the effects of the pedestrian green signal adjustment on clearance of the turning vehicles impeding the through traffic flow at the signalized intersections, and thereby, suggest some operational criteria for adjustment of the pedestrian green signal. In order to test such effects, the pedestrian green time was adjusted so that it could started a few seconds later than the vehicle green time during peak hours, and thereby, the turning vehicle volume not cleared at the intersection was measured by extending the time gap by 2 seconds. (In general, the pedestrian green signal turns on at the same time as the vehicle green signal.) The results of this test can be summed up as follows; first, the longer the time gap was, the turning vehicle volume not cleared from the intersection decreased more. Second, in case there existed a storage space between intersection and crosswalk the effect of the turning vehicles on the through traffic flows was minimal. Third, at the pelican, the effect of the turning vehicles on the through traffic flow was minimal due to the structure of the intersection and the phase sequence. In conclusion, it was found that the adjustment of pedestrian green signal had the effect of enhancing the intersection operation. When adjusting the pedestrian green signal, it was deemed necessary to thoroughly survey the geometric structure of the intersection and collect the data on the turning traffic volume and thereby, apply the results of analysis flexibly to each intersection.

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The Response Characteristics of Push-over and Nonlinear Time History Analysis with Variations in the Upper Stories of the Mixed Building Structure (복합구조물의 상부층수 변화에 따른 탄소성 정적 및 동적 응답특성)

  • 강병두;전대한;김재웅
    • Journal of the Earthquake Engineering Society of Korea
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    • v.5 no.5
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    • pp.73-83
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    • 2001
  • The mass and stiffness of upper wall-lower frame system(mixed building structures) change sharply at transfer floor due to different structural system in upper and lower part. These mixed building structures generally show the stiffness, weight or geometric vertical irregularities. The purpose of this study is to investigate the response characteristics of these structures by push-over analysis and nonlinear time history analysis. For four types of analysed models, only the variation of upper wall stories was considered. The conclusions of this study are following; (1) In the push-over analysis, yielding hinges in beams and columns of lower frame occurred at the base shear of similar magnitude in all models. But as the number of stories of upper wall increases, yielding hinges at ends of coupling beams were observed in the small magnitude of base shear. (2) In the nonlinear time history analysis, yielding of lower frame occurred at beams with as small ground acceleration as 55gal, and in upper walls yielding was concentrated on coupling beams and shear walls near the transfer floor. (3) As the number of stories of upper walls decreases, the story stiffness of the lower frames decreased relatively and the occurrence of soft stories in the lower frame was observed.

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Drivers' Workloads through the Driving Vehicle Test at Intersections (교차로 실차주행 실험을 통한 운전자 부하요인에 관한 연구)

  • Seo, Im-Ki;Park, Je-Jin;Sung, Soo-Lyeon;NamGung, Moon
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.11 no.3
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    • pp.112-123
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    • 2012
  • Different from general roads, intersections are the points where roads having different geometric structure and traffic operation system are met, and thereby they have complicated road structure and environmental factors. Various changes in driving patterns such as collision between vehicles approaching from roads adjacent to intersections, sudden stop of vehicles upon stop sign, quick start upon green lights kept increasing traffic accidents. It is known that traffic accidents are mainly derived from human factors. This study, in order to find out factors affecting drivers' behaviors within intersections, measured physiological responses such as brain wave, sight, driving speed, and so on by using state-of-the-art measuring device. As to concentration brain wave at individual intersections, it was found out that brain wave of testes was higher at main Arterial and accident-prone intersections compared with that of subsidiary Arterial. In addition, it was detected that drivers' visual activity was widely distributed at accident-prone intersections, meaning that it enhanced cautious driving from nearby vehicles. As to major factors causing drivers' workloads, factors from nearby vehicles such as deceleration, acceleration, lane change of nearby vehicles appeared as direct factors causing drivers' workloads, clarifying that these factors were closely related to causes of traffic accidents at intersections. Results of this study are expected to be used as basic data for evaluation of safety at intersections in consideration of physiological response of drivers.

A Study on Narrative in Louise Bourgeois' "You Better Grow Up" (루이즈 부르주아의 작품 의 내러티브 분석)

  • Oh, Sang-Il
    • Journal of Science of Art and Design
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    • v.9
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    • pp.49-87
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    • 2006
  • Narrative has broad domains. So it is related to the everything man faces in his daily life and also performed in various modes. Narrative is revealed through all media including a character, which is also applied to plastic art. And narrative objects formed beyond the differences in media aid forms of expression are commonly based on a language. The study on such objects which created a new conceit of narratology can be said to be a spiritual trend by which to understand the world and man from the viewpoint of a 'story'. Plastic art took high interest in narrative in the same period as the rise of postmodernist art in the latter half of the 20th century, which was also applied to sculpture. The researcher, therefore, investigated through the history of sculpture in the 20th century the process in which narrative was denied under the value system of modernism and reappeared with the quickening of postmodernism. And as a result this period could be briefly characterized by 'return to figure' and 'reappearance of narrative'. The is, such flow means that late sculpture converted its center of interest from simple geometric abstract forms to irregular, figurative images. The researcher chose as the subject of his study the work of Louise Bourgeois, who was judged to have performed narrative positively and successfully among a great number of performed narrative positively and successfully among a great number of postmodernist sculptors who adopted it as their own strategy of expression. As the central artist of postmodrnist sculpture, She expressed human desire and condition as sexuality through the introspection of her own personal experience in contrast to the character of pop art sensitive to external world. The researcher borrowed narrative semiotics as a method of analyzing more elaborately the problem about the generation of narrative shown in her works. For it, he selected as the sample work for analysis Bourgeois's , which were judged to contain narrative most abundantly and as the metaphor of a gaze and recollection presented a new woman self that sublimed love, hatred, and loneliness. The narrative in her works are characterized by introspection questioning one's own trauma. It has independent domain and characteristics and clearly reveals narrative and content-centered characteristics, which are commonly discovered in postmodernist sculpture. The researcher could more concretely and definitely understand the characteristics of narrative through figurative images by analyzing the sample work. The researcher wanted to call your attention to the fact that the sculpture in the late 20th century contained narrative commonly and uniformly despite being characterized by various expressions and modes. And the focused on highlighting the fact that the narrative was more effectively revealed through figurative images of human body and simultaneously analyzing the formalizing process and structure for narrative. Besides he wanted to argue that the position of narrative defining the characteristics of sculpture should be valued more justly. Also, such acceptance of narrative, which is discovered in the sculpture, will have to be understood as the characteristics of the period reflecting the cultural aspect of the present time.

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A Study on the Ubiquitous Wireless Tilt Sensors's Application for Measuring Vertical Deflection of Bridge (교량의 수직처짐 측정을 위한 유비쿼터스 무선경사센서 활용연구)

  • Jo, Byung Wan;Yoon, Kwang Won;Kim, Young Ji;Lee, Dong Yoon
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.15 no.3
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    • pp.116-124
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    • 2011
  • In this study, a new method to estimate the bridge deflection is developed by using Wireless Tilt Sensor. Most of evaluations of structural integrity, it is very important to measure the geometric profile, which is a major factor representing the global behavior of civil structure, especially bridges. In the past, Because of the lack of appropriate methods to measure the deflection curve of bridges on site, the measurement of deflection had been done restrictly within just a few discrete points along the bridge. Also the measurement point could be limited to locations installed with displacement transducers. So, in this study, the deflection of the structure was measured by wireless tilt sensor instead of LVDT(Linear Variable Differential Transformer). Angle change of tilt sensor shows structural behavior by the change of the resistor values which is presented to voltage. Moreover, the maximum deflection was calculated by changing the deflection angle which was calculated as V(measured voltage) ${\times}$F(factor) to deflection. The experimental tests were carried out to verify the developed deflection estimation techniques. Because the base of tilt measuring is the gravity, uniform measurement is possible independent of a measuring point. Also, measuring values were showed very high accuracy.

An NMR Study on the Phase Changes of Lipid Bilayers by Antimicrobial Peptides (항균성 펩타이드에 의한 지질 이중막의 상 변화에 대한 NMR 연구)

  • Kim, Chul
    • Journal of the Korean Chemical Society
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    • v.54 no.2
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    • pp.183-191
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    • 2010
  • The phase changes of 1-palmitoyl-$d_{31}$-2-oleoyl-sn-glycero-3-phosphatidylcholine (POPC_$d_{31}$) bilayers distorted by an antimicrobial peptide, a magainin 2 or an aurein 3.3 were investigated by using $^2H$ solid-state NMR (SSNMR) spectroscopy. From the theoretical simulation of the experimental $^2H$ solid-state NMR spectra the geometric structure constants and the lateral diffusion coefficients were obtained in the peptide-lipid mixture phases. Within five days of the peptide action on the lipid bilayers only the distorted alignment of the bilayers were measured but after 100 days an elliptic toroidal pore structure and an inverted hexagonal phase were formed in the presence of magainin 2 and aurein 3.3, respectively. In order to investigate the effect of an anionic lipid molecule on the actions of two peptides on the lipid bilayer, the same experiments were performed on the POPC_$d_{31}$/1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylglycerol (POPG) bilayer and the significant differences in the actions of two peptides on two bilayers of POPC_$d_{31}$ and POPC_$d_{31}$/POPG were measured.

Analysis of Landscape Structure Change for Riparian Buffer Zone KyangAn Watershed (경안천 유역 수변구역 경관구조 변화 분석)

  • Kim, Kyung-Tak;Kim, Joo-Hun
    • Journal of the Korean Association of Geographic Information Studies
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    • v.8 no.3
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    • pp.74-83
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    • 2005
  • The Riparian Buffer Zone has many potential values including the preservation of water quality as well as being ecologically friendly. This study aims to quantitatively analyze the landscape structure index of the Riparian Buffer Zone in the Kyoung-an stream and to produce base information necessary for proper management. The study used aerial images that were applied to geometric corrections for a time series from 1966 to 2000 for land data and also used FRAGSTATS, which is a type of ARCVIEW extension module, as an analysis tool. An analysis of land use change and the Landscape Index revealed that the area of farm land has decreased and that the area of residential property has increased. In addition, there was a slight change for land used for purposes other than farming or for residence. The results of analyzing the Landscape Structure Index, revealed that the NP has increased from 437 in 1966 to 695 in 2000. This data reveals that the change of land use is influenced by various artificial factors. The NPS, which represents the declining degree of patch, decreased from 9.441 to 5.934, revealing that the change of land use has been progressing considerably. In regard to forest areas, land use reduced somewhat but did not indicate a significant change. Therefore, an analysis of the total index reveals that the edge of patch has become more complicated and that the variation index of patch has increased significantly. However, this study reveals that barriers to block pollution have weakened as a result and that there is a need to concentrate on the implementation and the management of the Riparian Buffer Zone. Consequently, this study reveals that substantial research is necessary in order to carry out the proper management of the Riparian Buffer Zone, especially in light of the distribution type of each patch and the change in conditions regarding them.

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Geological Structure of the Metamorphic Rocks in the Muju-Seolcheon Area, Korea: Consideration on the Boundary of Ogcheon Belt and Ryeongnam Massif (무주-설천 지역 변성암류의 지질구조: 옥천벨트와 영남육괴의 경계부 고찰)

  • Kang, Ji-Hoon
    • The Journal of the Petrological Society of Korea
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    • v.28 no.1
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    • pp.25-38
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    • 2019
  • The Muju-Seolcheon area, which is known to be located in the boundary of Ogcheon Belt and Ryeongnam Massif (OB-RM), consists of age unknown or Precambrian metamorphic rocks (MRs) [banded biotite gneiss, metasedimentary rocks (black phyllite, mica schist, crystalline limestone, quartzite), granitic gneiss, hornblendite], Mesozoic sedimentary and igneous rocks. In this paper are researched the structural characteristics of each deformation phase from the geometric and kinematic features and the developing sequence of multi-deformed rock structures of the MRs, and is considered the boundary location of OB-RM with the previous geochemical, radiometric, structure geological data. The geological structure of this area is at least formed through four phases (Dn-1, Dn, Dn+1, Dn+2) of deformation. The Dn-1 is the deformation which took place before the formation of Sn regional foliation and formed Sn-1 foliation folded by Fn fold. The Dn is that which formed the Sn regional foliation. The predominant Sn foliation shows a NE direction which matches the zonal distribution of MRs. A-type or sheath folds, in which the Fn fold axis is parallel to the direction of stretching lineation, are often observed in the crystalline limestone. The Dn+1 deformation, which folded the Sn foliation, took place under compression of NNW~NS direction and formed Fn+1 fold of ENE~EW trend. The Sn foliation is mainly rearranged by Fn+1 folding, and the ${\pi}$-axis of Sn foliation, which is dispersed, shows the nearly same direction as the predominant Fn+1 fold axis. The Dn+2 deformation, which folded the Sn and Sn+1 foliations, took place under compression of E-W direction, and formed open folds of N-S trend. And the four phases of deformation are recognized in all domains of the OB-RM, and the structural characteristics and differences to divide these tectonic provinces can not be observed in this area. According to the previous geochemical and radiometric data, the formation or metamorphic ages of the MRs in and around this area were Middle~Late Paleproterozoic. It suggests that the crystalline limestone was at least deposited before Middle Paleproterozoic. This deposition age is different in the geologic age of Ogcheon Supergroup which was recently reported as Neoproterozoic~Late Paleozoic. Therefore, the division of OB-RM tectonic provinces in this area, which regards the metasedimentary rocks containing crystalline limestone as age unknown Ogcheon Group, is in need of reconsideration.

The Optimal Configuration of Arch Structures Using Force Approximate Method (부재력(部材力) 근사해법(近似解法)을 이용(利用)한 아치구조물(構造物)의 형상최적화(形狀最適化)에 관한 연구(研究))

  • Lee, Gyu Won;Ro, Min Lae
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.13 no.2
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    • pp.95-109
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    • 1993
  • In this study, the optimal configuration of arch structure has been tested by a decomposition technique. The object of this study is to provide the method of optimizing the shapes of both two hinged and fixed arches. The problem of optimal configuration of arch structures includes the interaction formulas, the working stress, and the buckling stress constraints on the assumption that arch ribs can be approximated by a finite number of straight members. On the first level, buckling loads are calculated from the relation of the stiffness matrix and the geometric stiffness matrix by using Rayleigh-Ritz method, and the number of the structural analyses can be decreased by approximating member forces through sensitivity analysis using the design space approach. The objective function is formulated as the total weight of the structures, and the constraints are derived by including the working stress, the buckling stress, and the side limit. On the second level, the nodal point coordinates of the arch structures are used as design variables and the objective function has been taken as the weight function. By treating the nodal point coordinates as design variable, the problem of optimization can be reduced to unconstrained optimal design problem which is easy to solve. Numerical comparisons with results which are obtained from numerical tests for several arch structures with various shapes and constraints show that convergence rate is very fast regardless of constraint types and configuration of arch structures. And the optimal configuration or the arch structures obtained in this study is almost the identical one from other results. The total weight could be decreased by 17.7%-91.7% when an optimal configuration is accomplished.

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