• Title/Summary/Keyword: Geometric structure

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Running Safety Analysis of Railway Vehicle passing through Curve depending on Rail Inclination Change (레일 경좌 변화에 따른 곡선부 통과열차의 주행안전성 해석)

  • Kim, Moon Ki;Eom, Beom Gyu;Lee, Hi Sung
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.23 no.3
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    • pp.199-208
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    • 2013
  • So far today, there is a speed limit by the radius of curve based on operation regulation in domestic railway, however a study for the maximum running speed at the curved section without any derailment would be necessary. The two major factors related to the running safety of railway vehicle are classified as the railway vehicle condition and the track condition. In terms of the rail inclination among many other factors, the determination of rail inclination within the possible limit is necessary for the geometrical structure of the optimum track. The disregard of the geometrical parameter related to the rail inclination may cause a serious problem to the running safety of railway vehicle. This study is focusing on the analyzing of running safety regard to the change of rail inclination among the many other parameters to improve derailment safety, so that there is an affection analysis of the running safety regard to the change of rail inclination in the ideal and geometric track condition. Also There is an affection analysis of the running safety regard to the simultaneous change of rail inclination and the running speed at the curved section. According to analysis results of running safety, In case that the left and right rail inclination are 1/40, the running safety of this condition defined than other conditions. Also, the rail inclination of conventional lines is 1/40, Therefore, the railway vehicle passing through curve is safe when the railway vehicle runs in conventional lines.

Environmental Impacts of Stone Quarry Exploitation - Aquatic Macroinvertebrate Community and Quarry Locality (수생태계에 미치는 석산개발의 영향 - 생물군집과 입지유형을 중심으로)

  • Lee, Sung Jin;Kim, Myoung Chul;Kim, Ji Young;Ro, Tae Ho
    • Journal of Korean Society on Water Environment
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    • v.21 no.4
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    • pp.368-378
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    • 2005
  • Inorganic matters originated from stone quarries and manufacturing plants could alter the ecological characteristics of adjacent aquatic systems, especially the structure and function of benthic macroinvertebrate community. In such situation, the locality of stone quarry and the quantity of inorganic matters would be important factors that determined the disturbing strength to the benthic macroinvertebrate community. Locality patterns of stone quarries were classified into 3 types in relation to the stream ecosystem; stream-proximity, upstream-inclusion and tributary-inclusion type. In the result of species:abundance analysis, stone quarry B (upstream-inclusion type) showed geometric distribution, while others showed broken-stick distribution pattern. The benthic macroinvertebrate communities closer to stone quarries showed smaller species numbers and standing crops among all types of stone quarries. However the values of species evenness index were not seriously different between controls and directly affected sites. These results indicated that the effect of inorganic disturbance would differ from those of organic pollution that induced the highly dominant state occupied by tolerant species. Number of occurred species, standing crops, community indices and biotic indices indicated that the community of upstream-inclusion type was the most seriously damaged from the inorganic disturbance, and the community would be very simple and unstable. Tributary-inclusion stone quarry heavily damaged to tributary system in biologically, but influence to the main stream seemed to be depended on the scale of main stream. Among 3 types of stone quarry localities, stream-proximity type induced the least damages to benthic macroinvertebrate community, though the degrees of damage were different along with distances between stream and stone quarry.

Method of Quasi-Three Dimensional Stability Analysis of the Root Pile System on Slope Reinforcement (사면보강 뿌리말뚝공법의 준3차원적 안정해석기법)

  • Kim, Hong-Taek;Gang, In-Gyu;Park, Sa-Won
    • Geotechnical Engineering
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    • v.13 no.5
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    • pp.101-124
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    • 1997
  • The root pile system is insitu soil reinforcement technique that uses a series of reticulately installed micropiles. In terms of mechanical improvement by means of grouted reinform ming elements, the root pile system is similar to the soil nailing system. The main difference between root piles and soil nailing are due to the fact that the reinforcing bars in root piles are normally grouted under high pressure and that the alignments of the reinforcing members differ. Recently, the root pile system has been broadly used to stabilize slopes and retain excavations. The accurate design of the root pile system is, however, a very difficult tass owing to geometric variety and statical indetermination, and to the difficulty in the soilfiles interaction analysis. As a result, moat of the current design methods have been heavily dependent on the experiences and approximate approach. This paper proposes a quasi-three dimensional method of analysis for the root pile system applied to the stabilization of slopes. The proposed methods of analysis include i) a technique to estimate the change in borehole radium as a function of the grout pressure as well as a function of the time when the grout pressure is applied, ii) a technique to evaluate quasi -three dimensional limit-equilibrium stability for sliding, iii) a technique to predict the stability with respect to plastic deformation of the soil between adjacent root piles, and iv) a quasi -three dimensional finite element technique to compute stresses and dis placements of the root pile structure barred on the generalized plane strain condition and composite unit cell concept talon형 with considerations of the group effect and knot effect. By using the proposed technique to estimate the change in borehole radius as a function of the grout pressure as well as a function of the time, the estimations are made and compar ed with the Kleyner 8l Krizek's experimental test results. Also by using the proposed quasi-three dimensional analytical method, analyses have been performed with the aim of pointing out the effects of various factors on the interaction behaviors of the root pile system.

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Analysis and design of demountable steel column-baseplate connections

  • Li, Dongxu;Uy, Brian;Aslani, Farhad;Patel, Vipul
    • Steel and Composite Structures
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    • v.22 no.4
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    • pp.753-775
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    • 2016
  • This paper aims to investigate the demountability of steel column-baseplate connections subjected to monotonic and cyclic loading. This paper presents the finite element analysis of steel column-baseplate connections under monotonic and cyclic loading. The finite element model takes into account the effects of material and geometric nonlinearities. Bauschinger and pinching effects were also included in the developed model, through which degradation of steel yield strength in cyclic loading can be well simulated. The results obtained from the finite element model are compared with the existing experimental results. It is demonstrated that the finite element model accurately predicts the initial stiffness, ultimate bending moment strength of steel column-baseplate connections. The finite element model is utilised to examine the effects of axial load, baseplate thickness, anchor bolt diameter and position on the behaviour of steel column-baseplate connections. The effects of various parameters on the demountability of steel column-baseplate connections are investigated. To achieve a demountable and reusable structure, various design parameters need to be considered. Initial stiffness and moment capacity of steel columnbaseplate connections are compared with design strengths from Eurocode 3. The comparison between finite element analysis and Eurocode 3 indicates that predictions of initial stiffness for semi-rigid connections should be developed and improved design of the connections needs to be used in engineering practice.

Prediction of Three-Dimensional Strip Profile for 6-High Mill in Thin-Strip Rolling (6 단 압연기의 극박 압연공정에서 3 차원 판 형상 예측)

  • Lee, Sang-Ho;Song, Gil-Ho;Lee, Sung-Jin;Kim, Byung-Min
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.35 no.8
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    • pp.855-861
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    • 2011
  • We predict the rolled-strip profile for a 6-high mill using thin rolling theory and a numerical model. In the numerical model, we calculate the distributions of the contact pressures between the rolls and the rolling pressure between the strip and the work roll in the transverse direction using the geometric structure of the 6-high mill and the boundary conditions. We determine the distribution of the rolling pressure in the rolling direction via a thin-foil rolling model using Fleck's theory. We calculate the three-dimensional elastic deformation of the work roll using the pressures of the width and rolling directions. We then obtain the three-dimensional strip profile via the elastic deformation of the work roll during the rolling process. The profile is verified by a thin cold-rolling test and FE simulation.

A Genetic Analysis of Taoyuan Pig and Its Phylogenetic Relationship to Eurasian Pig Breeds

  • Li, Kuan-Yi;Li, Kuang-Ti;Cheng, Chun-Chun;Chen, Chia-Hsuan;Hung, Chien-Yi;Ju, Yu-Ten
    • Asian-Australasian Journal of Animal Sciences
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    • v.28 no.4
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    • pp.457-466
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    • 2015
  • Taoyuan pig is a native Taiwan breed. According to the historical record, the breed was first introduced to Taiwan from Guangdong province, Southern China, around 1877. The breed played an important role in Taiwan's early swine industry. It was classified as an indigenous breed in 1986. After 1987, a conserved population of Taoyuan pig was collected and reared in isolation. In this study, mitochondrial DNA sequences and 18 microsatellite markers were used to investigate maternal lineage and genetic diversity within the Taoyuan pig population. Population differentiation among Taoyuan, Asian type, and European type pig breeds was also evaluated using differentiation indices. Only one D-loop haplotype of the Taoyuan pig was found. It clustered with Lower Changjiang River Basin and Central China Type pig breeds. Based on the polymorphism of microsatellite markers, a positive fixation index value ($F_{IS}$) indicates that the conserved Taoyuan population suffers from inbreeding. In addition, high $F_{ST}$ values (>0.2105) were obtained, revealing high differentiation among these breeds. Non-metric multi-dimensional scaling showed a clear geometric structure among 7 breeds. Together these results indicate that maternally Taoyuan pig originated in the Lower Changjiang River Basin and Central China; however, since being introduced to Taiwan differentiation has occurred. In addition, Taoyuan pig has lost genetic diversity in both its mitochondrial and nuclear genomes.

Mathematical and Astronomical Implication of Taegeuk Stone Rods of Kameun Temple Site (감은사지 태극 장대석의 수리천문학적 의미(感恩寺址 太極 長臺石의 數理天文學的 意味))

  • Baek, In-Soo;Kim, Tae-Sik
    • The Journal of the Korea Contents Association
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    • v.11 no.3
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    • pp.460-466
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    • 2011
  • Kameun temple was constructed in A.D. 682 after 46 year after Chumsungdae was constructed. This paper discusses the scientific implication of Taegeuk stone rods of Kameun temple site through the geometric analysis of their engraved figures. So we can estimate that the west Taegeuk of Kameun temple site has 2 circles comparing the path of the moon with that of the sun leading to the asymmetry in its emblem(Taegeuk) and the east Taegeuk of Kameun temple site has 1 circle representing the path of the sun. The Taegeuks along with around 30 equilateral triangles representing the north latitude $35.8^{\circ}$ give the explicit information of period of the orbit of the moon and the sun. These mathematical methods can explain some relics structure of antiquity with a few historical expounds.

a study of typeface (심청전 목판 체 연구)

  • 안상수
    • Archives of design research
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    • v.14
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    • pp.321-333
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    • 1996
  • The typeface of the Shhnch 'ongjon woodblocks is unsophisticated and old-fashioned while at the same time having a tidiness and strength that give it its special appeal. This is the typeface used in publishing novPls for sale to the common people during the latter half of the Choson Dynasty_ Their demands could not be satisfied with most currently available literature. which was intended to suit the tastes of the official class. As a result of a development to overcome the unbalanced use of space characteristic of letterforms that followed the geometric principles of early Hangul. the typeface followed the refined. feminine "hrushstroke" style of kungch 'e. establishing itself as a "rough" face displaying the characteristics of carved. woodblock printing in answer to the needs of the common p-eople who had the greatest need of Hangul during the time of its f1owering. The Shhnch 'ongjon face is characterized by thin horizontal strokes. thick vertical strokes. and the appearance of being condensed left to right. They possess simple yet varied form. With these characteristics the Shimch' ongjon typeface. if revived and compared to other typefaces. has a beauty of structure and composition and a unique. modern lmage with excellent readability. giving it great significance for modern r langul typography.r langul typography.

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A Study on the Hand Values of Hanji Paper Yarn Fabric Treated with Persimmon Juice (감즙 처리된 한지사 소재의 Hand Value에 관한 연구)

  • Choi, Kyeong-Eun;Rhie, Jeon-Sook;Jung, Woo-Young
    • Journal of the Korea Fashion and Costume Design Association
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    • v.12 no.4
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    • pp.197-206
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    • 2010
  • The purpose of this study is to dye hanji/cotton fabrics using persimmon juice and to investigate the change in the hand fabrics. Using the Kawabata Evaluation System, we have examined the changes in the physical properties, primary hand value and total hand value. The dynamic characteristics of hanji/cotton fabrics have been explored by tensile, shear, bending, compression, surface properties, thickness and weight. As a result, it can be seen that the linearity of load-extension and tensile resilience are increased with the increase of the concentration and dyeing times of persimmon juice and tensile energy is decreased in the same condition. These behaviors are shown in the compression properties. Although the mechanism of persimmon juice dyeing has been widely discussed, it means that the fabrics dyed with persimmon juice become stiffened and the elasticity is increased with the introduction of persimmon on the fabrics studied. Bending rigidity and hysteresis of the bending moment are increased with the increase of the concentration and dyeing times of persimmon juice. Also, Geometrical roughness, expressed in SMD is increased with increasing the concentration and dyeing times of persimmon juice, compared with as-received. It indicates that these results are due to the geometric structure of hanji yarn and the introduction of persimmon juice on the fabrics studied. The fullness and softness with the soft feeing are increased a little due to the tannin component of persimmon juice introduced on the fiber surface.

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Analysis of Driving Conditions and Traffic Accidents in the Case of Trumpet Interchange Ramps (트럼펫 IC 램프의 운전조건과 교통사고 분석)

  • Kim, Tae-Yeong;Park, Byeong-Ho
    • Journal of Korean Society of Transportation
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    • v.25 no.1 s.94
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    • pp.73-79
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    • 2007
  • This study deals with traffic accidents at the ramps of trumpet interchanges. The purpose of the study is to analyze the relations between tke turning direction of ramps (and combinations with other factors) and traffic accidents. In Pursuing this analysis, this study gives particular attention to the combination of turning direction and grade and the combination of turning direction and radius of curvature in the case of the trumpet interchange ramps. The null hypothesis tests show that the average accident number and average accident rate ate rejected at the 90% and 95% significance level respectively Also. the null hypothesis tests show that the combinations or turning direction and Evade as well as turning direction and radius are all rejected at the 95% significance level. In summary, right turn movements ate more dangerous than left turns on the trumpet interchange vamps. Also, ramps with a right turn and up grade or with a left turn and radius more than 200m have more traffic accident Potential than other types of ramps.