• Title/Summary/Keyword: friction area

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A Study on the Functional Distribution of Port Hinterland Construction and Management among Governments: Focused on the Busan New Port (정부 간 항만배후단지 개발·관리 기능배분에 관한 연구: 부산항 신항 중심)

  • Kang, Yunho;Kim, Bo-Young
    • Journal of Navigation and Port Research
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    • v.42 no.3
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    • pp.227-236
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    • 2018
  • The Busan New Port and its hinterland have not operated smoothly due to the complicated laws and various related organizations. Thus, many projects involving the port are not matched with its purpose of establishment. In particular, a large-scale apartment complex, which was constructed without a negotiation among the related organizations, is disturbing the port's logistics function. Also, the construction and management of every traffic facilities are conducted by various organizations due to the functions for the facilities are dispersed among them, which has given rise to chaos and responsibility-shifting. As a result, worries about the friction among the organizations and the loss of function of the port hinterland exist. This paper analyzes the problems of inter-governmental functional distributions in the construction and management of the port hinterland of the Busan New Port based on the principles (theories) of functional distribution. In addition, this paper proposes improvements for the functional distribution. The results of the analysis indicated that the functions for housing and traffic facilities were duplicated and dispersed among organizations, resulting in an unclear division of responsibilities. Finally, the paper proposed solutions for the problems: the institutionalization of an administrative conference system among related organizations, using an integrated administration for a wide area (contracting-out, association among local governments), and establishing a special-purpose local government (association among local governments, BPA).

The Characteristic of Strength for a Lime Stone in Donghae Area and Harden Cement Milk of Super Injection Grouting (동해 석회암과 SIG 고결체의 강도특성)

  • Park, Young-Ho;Kim, Nak-Young;Hong, Sa-Myun;Yook, Jeong-Hoon;Kim, Ki-Seog
    • Proceedings of the Korean Geotechical Society Conference
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    • 2004.03b
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    • pp.137-145
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    • 2004
  • Limestone zone in korea have been distributed to diagonal line so that it is wide from the Gangwondo to the Jeonlanamdo. The limestone cavity and fractured zone were formed by chemical weathering. Limestone cavity and fractured zone was reinforced with cemented milk(w/c=60%)by high pressure jet grouting by tripple -pipe to establish bridge foundation on the ground condition like limestone cavity. To analyze property of limestone and solid of cement milk(w/c=65%), mixed solid of cement, core NX size in the limestone cavity and fractured zone and compressive strength. Seismic tomograpy exploration was pcrforn1cd to analyze deformation modulus of limestone. The analysis suggests that deformation modulus of limestone has effect on uniaxial compressive strength, seismic velocity, seismic elasticity modulus. Average static elasticity modulus of limestone is $5.08{\times}10^5kgf/cm^2$, cement and coal mixed solid is $0.25{\times}10^5kgf/cm^2$, $0.095{\times}10^5kgf/cm^2$. Average seismic velocity of limestone is 5.240m/sec, cement and coal mixed solid is 2,211.3m/sec, 1,447.5m/sec. Average uniaxial compressive strength of limestone was $1,221.3kgf/cm^2$ and limestone specimen mixed with cement milk and solid of cement milk mixed with coal were $125.22kgf/cm^2$, $35kgf/cm^2$ each other. Average friction angle of limestone was $49.14^{\circ}$ and limestone specimen mixed with cement milk and solid of cement milk mixed with coal were $38.39^{\circ}, 25.83^{\circ}$ each other. Average cohesion of limestone was $137.7kgf/cm^2$ and limestone specimen mixed with cement milk and solid of cement milk mixed with coal were $23.5kgf/cm^2$, $15.5kgf/cm^2$ each other. Average deformation modulus of limestone was $2.84{\times}10^5kgf/cm^2$ and limestone specimen mixed with cement milk and solid of cement milk mixed with coal were $0.4{\times}10^5kgf/cm^2, 0.12{\times}10^5kgf/cm^2$ each other. It was analyzed that the elasticity and uniaxial compressive strength, seismic velocity of solid of cement milk mixed limestone pieces and coal had an highly interrelation regardless of existence of limestones pieces and coal but it had shown that limestones had an lower interrelation. In case of field seismic velocity and deformation of limestone, SIC solid of cement milk mixed with coal and limestone pieces had an highly interrelation.

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Experimental Study on the Shear Strength Characteristics of the Saturated Sand (포화(飽和)모래의 전단강도특성(剪斷强度特性)에 관(關)한 실험적(實驗的) 연구(研究) -대구지역(大邱地域) 낙동강(洛東江) 모래에 대해-)

  • Kim, Young Su;Seo, In Shik;Kim, Byoung Tak
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.14 no.6
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    • pp.1417-1431
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    • 1994
  • In this study, shear strength characteristics of the Nak-Dong river sand in Taegu area are investigated by triaxial compression test, considering shear strain control velocity, relative density, and confining pressure. The results from Lade model and Modified Lade model are compared with the measured value in the laboratory test. The results by the change of shear strain control velocity, relative density, and confining pressure are as follows; 1) The stress limit, which can be Coulomb's law about the Nak-Dong river sand, have ranged 120~200 kpa at 0.08%/min and 120~150 kpa at 0.5%/min. These limits are smaller than that of the calcareous sand and the well-graded, quartz sand. 2) The parameters needed to Lade model and Modified Lade model are much affected by the strain control velocity and the relative density. Consequently, in the field, it is important to use parameters aptly after accurately understanding both the loading condition and subsoil condition. 3) Overall, the principal stress ratio obtained from constitutive model equations is not affected by the control velocity, but both the relative density and confining pressure affect the result of constitutive model equations. Consequently, the study on the various conditions about the relative density and confining pressure is needed to accurately predict the stress-strain behavior on the Nak-Dong river sand. 4) For the range of the used confining pressure in the study, the Lade model shows better agreements with the measured value than the Modified Lade model, comparing the measured value with the principal stress ratio at failure and the internal friction angle of failure envelope obtained from the Lade model and Modified Lade model.

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Amber Information Design for Supporting Safe-Driving Under Local Road in Small-scale Area (국지지역에서의 안전운전 지원을 위한 경보정보 설계)

  • Moon, Hak-Yong;Ryu, Seung-Ki
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.9 no.5
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    • pp.38-48
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    • 2010
  • Adverse weather (e.g. strong winds, snow and ice) will probably appear as a more serious and frequent threat to road traffic than in clear climate. Another consequence of climate change with a natural disastrous on road traffic is respond to traffic accident more the large and high-rise bridge zone, tunnel zone, inclined plane zone and de-icing zone than any other zone, which in turn calls for continuous adaption of monitoring procedures. Accident mitigating measures against this accident category may consist of intense winter maintenance, the use of road weather information systems for data collection and early warnings, road surveillance and traffic control. While hazard from reduced road friction due to snow and ice may be eliminated by snow removal and de-icing measures, the effect of strong winds on road traffic are not easily avoided. The purpose of the study described here, was to design of amber information the relationship between traffic safety, weather, user information on road weather and driving conditions in local-scale Geographic. The most applications are the optimization of the amber information definition, improvements to road surveillance, road weather monitoring and improved accuracy of user information delivery. Also, statistics on wind gust, surface condition, vehicle category and other relevant parameters for wind induced accidents provide basis for traffic control, early warning policies and driver education for improved road safety at bad weather-exposed locations.

Studies on a Plan for Afforestation at Tong-ri Beach Resort - Analysis of Factors Causing Disasters around Beach - (통리해수욕장(桶里海水浴場) 녹지대조성(綠地帶造成)에 관(關)한 연구(研究)(I) - 사구지주변(砂丘地周邊)의 재해요인분석(災害要因分析) -)

  • Cho, Hi Doo
    • Journal of Korean Society of Forest Science
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    • v.77 no.2
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    • pp.178-185
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    • 1988
  • This study is carried out for analyzing the factors causing several disasters occurring around beach area in order to set a plan for an afforestation which will fulfill its function as facilities for prevention of disasters and for relaxation around beach resort at Tong-ri, Pokil-my$\bar{o}$n, Wando-gun. The results are as follows : 1. The main wind direction was summer was SE. 2. The first class in the rate of frequency of the hourly average wind speed and the instantaneous wind speed in summer were 2.1-3.0m/sec (29.2%) and 1.1-2.0m/sec (30.6%) respectively. 3. The particle sizes of the dune sands was a little small (82.5% in 0.125 to 0.25mm, $D_{50}=0.178mm$). 4. The mineral composition and the chemical components were as follows : The main mineral : Quartz The accessary minerals : Calcite, Feldspars(Orthoclase), Sericite. The chemical components : $SiO_2$ ; 75.6%. $Al_2O_3$ ; 8.1%, CaO ; 7.76%, Ign. loss ; 6.8%, MgO ; 0.23%, $K_2O$ ; 0.72%, $Na_2O$ ; 0.41%, $Fe_2O_3$ ; 0.32%. 5. The threshold friction velocity equation for the diameter class of the dune sands was $y=4.191x^{0.221}$. 6. The amount of floating salt was maximum at the point of 65m away from beach line, dropped abruptly at 135m and remained almost same on its way to the inland. The equation of the amount of floating salt was $y=28.181{\times}(-0.369^x)$. 7. The amount of extracted salt(33%) in seawater in summer was the same as the one of the nearest seawater of Korea.

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Magnetic Resonance Elastography (자기 공명 탄성법)

  • Kim, Dong-Hyun;Yang, Jae-Won;Kim, Myeong-Jin
    • Investigative Magnetic Resonance Imaging
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    • v.11 no.1
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    • pp.10-19
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    • 2007
  • Conventional MRI methods using T1-, T2-, diffusion-, perfusion-weighting, and functional imaging rely on characterizing the physical and functional properties of the tissue. In this review, we introduce an imaging modality based on measured the mechanical properties of soft tissue, namely magnetic resonance elastography (MRE). The use of palpation to identify the stiffness of tissue remains a fundamental diagnostic tool. MRE can quantify the stiffness of the tissue thereby providing a objective means to measure the mechanical properties. To accomplish a successful clinical setting using MRE, hardware and software techniques in the area of transducer, pulse sequence, and imaging processing algorithm need to be developed. Transducer, a mechanical vibrator, is the core of MRE application to make wave propagate invivo. For this reason, considerations of the frame of human body, pressure and friction of the interface, and high magnetic field of a MRI system needs to be taken into account when designing a transducer. Given that the wave propagates through human body effectively, developing an appropriate pulse sequence is another important issue in obtaining an optimal image. In this review paper, we introduce the technical aspects needed for MRE experiments and introduce several applications of this new field.

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A Study on Hot Extrusion Characteristics of Particulate Reinforced Aluminium Matrix Composite. (입자분산강화 알루미늄 복합재의 압출가공특성에 관한 연구)

  • Gwon, Hyeok-Cheon;Yun, Ui-Park
    • Korean Journal of Materials Research
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    • v.5 no.8
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    • pp.953-959
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    • 1995
  • It was investigated that reinforced species, billet condition and extrusion variation in Al 6061 composite material effected on extrusion process of particulate reinforced composite material. The strength of composite material with reinforcement species revealed SiC$\sub$w/> A1$_2$O$\sub$3f/ > A1$_2$O$\sub$3f/ > A1$_2$O$\sub$3f/ orderly. K$\sub$w/ increased as volute fraction increased in all composite material. The composite materials reinforced by A1$_2$ $O_3$required the larger pressure in hot extrusion process than those by SiC$\sub$p/ at all condition. Extrusion process tended to decrease as the semi-angle of extrusion dies increased because larger contact area caused larger shear friction. Extrusion temperature went up about 50$^{\circ}C$ in low elevated deformation temperature. In extrusion temperature above 500$^{\circ}C$, severe tearing occurred on extrusion surface. More reinforcement in volume fraction, more hot tearing.

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Assessment of Earthquake Induced Landslide Susceptibility with Variation of Groundwater Level (지하수위 변화에 따른 지진 유발 산사태의 취약섬 분석)

  • Kim, Ji-Seok;Park, Hyuek-Jin;Lee, Jung-Hyun
    • Economic and Environmental Geology
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    • v.44 no.4
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    • pp.289-302
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    • 2011
  • Since the frequency of the earthquake occurrence in Korean peninsular is continuously increasing, the possibility that massive landslides are triggered by earthquake is also growing in Korea. Previously, the landslide is known to be induced by large magnitude earthquake, whose magnitude is larger than 6.0. However, the landslide can be induced by only small magnitude earthquake, especially in the fully saturated soil. Therefore, the susceptibility of landslide caused by small magnitude earthquake in fully saturated soil is analyzed in this study. For that, the topographical and geological characteristics of the site were obtained and managed by GIS software. In the procedure of the study, slope angle, cohesion, friction angle, unit weight of soil were obtained and constructed as a spatial database layer. Combining these data sets in a dynamic model based on Newmark's displacement analysis, the landslide displacements were estimated in each grid cell. In order to check out the possibility of the earthquake induced landslides, the level of the groundwater table is varied from dry to 80% saturated soil. In addition, in order to analyze the effect of the magnitude of earthquake and distance to epicenter, four different earthquakes epicenters were considered in the study area.

Prediction of Brittle Failure within Mesozoic Granite of the Daejeon Region (대전지역 중생대 화강암 암반 내 취성파괴 예측연구)

  • Jang, Hyun-Sic;Choe, Mi-Mi;Bae, Dae-Seok;Kim, Geon-Young;Jang, Bo-An
    • The Journal of Engineering Geology
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    • v.25 no.3
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    • pp.357-368
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    • 2015
  • Brittle failure of Mesozoic granite in the Daejeon region is predicted using empirical analysis and numerical modeling techniques. The input parameters selected for these techniques were based on the results of laboratory tests, including damage-controlled tests. Rock masses that were considered to be strong during laboratory testing were assigned to "group A" and those considered to be extremely strong were assigned to "group B". The properties of each group were then used in the analyses. In-situ stress measurements, or the ratio of horizontal to vertical stress (k), were also necessary for the analyses, but no such measurements have been made in the study area. Therefore, k values of 1, 2, and 3 were assumed. In the case of k=1, empirical analysis and numerical modeling show no indication of brittle failure from the surface to1000 m depth. When k=2, brittle failure of the rock mass occurs at depths below 800 m. For k=3, brittle failure occurs at depths below 600 m. Although both the Cohesion Weakening Friction Strengthening (CWFS) and Mohr-Coulomb models were used to predict brittle failure, only the CWFS model performed well in simulating the range and depth of the brittle failure zone.

Computation of Tides for Off Kyungnam Coast with Dynamically Combined Two-Dimensional and Three-Dimensional Tidal Model (2차원 및 3차원 동적복합조석모형에 의한 경남해역의 조석산정)

  • 최병호;우승범
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.7 no.2
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    • pp.176-197
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    • 1995
  • Two-dimensional and three-dimensional structures of tidal currents on southeastern waters of Korea off Kyungnam coast were investigated via a series of numerical models based on dynamic principles. With a two-dimensional tidal model, tidal regimes of major eight tidal constituents (M$_2$, S$_2$, K$_1$, O$_1$, N$_2$, K$_2$, P$_1$, Q$_1$) were computed. Model results showed that the computed results were in good agreement with coastal observations. On the basis of these results the model was further improved to compute three-dimensional structure of tidal current in inner Jinhai and Masan Bay regions of the model area where severe pollutions occur due to red tide by combination of the previous two-dimensional model and inner three-dimensional model. For this work, three-dimensional Galerkin-Spectral model and two-dimensional depth-integrated model are dynamically combined by the method presented by Davies (1980). In addition to the previous work by Davies, the advective term and quadratic bottom friction term are included in present Three-dimensional numerical model. The computed results of M$_2$ tidal current ellipses with respect to depth showed general agreements with those of current observations by KORDI (1990).

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