• Title/Summary/Keyword: transitional flow

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Depositional Environments and Characteristics of Surface Sediments in the Nearshore and Offshore off the Mid-Western Coast of the Korean Peninsula (한반도 중서부 근 ${\cdot}$ 외해의 표층 퇴적물 특성과 퇴적환경)

  • Oh, Jae-Kyung;Kum, Byung-Chul
    • Journal of the Korean earth science society
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    • v.22 no.5
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    • pp.377-387
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    • 2001
  • In order to elucidate sedimentation processes and depositional environments in transitional area between continental shelf and coastal zone, sedimentologic study has been done with 84 surface sediments sampled in nearshore/offshore off the mid-western coast of the Korean Peninsula for 3 years (1996${\sim}$1999). The surface sediment can be classified into 4 facies (gravelly sand, sand, silty sand and sandy silt). Mean grain size, sorting, skewenss and kurtosis varies -0.39${\sim}7.82{\Phi}$, 0.36${\sim}4.68{\Phi}$, -0.38${\sim}$0.86, -1.56${\sim}$3.43, respectively. The textural parameters show a finer-grained and poorly-sorted trend shoreward, northward and southward from the central part of the study area. The positively-skewed distribution and relationship of each textural parameters indicate a tide-dominated depositional environment. According to C/M diagram, there are 3 different domains (mode A, B, C) of sediment transport mode. The northern part is characterized by bedload transport (mode A) and represents co-influence of wave and tide, whereas domain C in the southern part is controlled by uniform suspension transport (mode C), correlating with sandy-silt area. In the broad middle area, transport processes are complex (the mixture of bedload, graded suspension and uniform suspension; mode B). Hence, the subdivision depositional environments of this study area may be classified by 3 depositional environments dependent on the interplay of sediment supplies from river, relict sediments and hydrologic conditions. In results, the nearshore and offshore areas are thus characterized as a mixing zone between coastal terrigenous sediments and relict sediments in the continental shelf by complex processes (tide, wave and river flow). These sedimentation processes play an important role in producing distinct sedimentologic features in the transitional zone linking coastal and shelfal areas.

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Anti-cancer Effects by Saussurea lappa Clarke in Highly-metastatic MDA-MB-231 Breast Cancer Cells (전이성 유방암 세포주에 대한 당목향의 항암효과탐색)

  • Kim, Chi-Hong;Choi, Youn-Kyung;Kim, Woo-Young;Shin, Yong-Cheol;Ko, Seong-Gyu
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.25 no.6
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    • pp.968-974
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    • 2011
  • Saussurea lappa Clarke is a well-known transitional medicine in Asia including Korea, China and Japan. It has been reported that Clarke has diverse effects such as anti-viral, anti-inflammatory, anti-cancer in human gastric cells and human prostate cancer cells. However, the anti-cancer effects and the mechanism of actions of Saussurea lappa Clarke are still unknown in breast cancer. In this study, we observed that Saussurea lappa Clarke inhibits the cell growth in a dose- and time-dependent manner in highly-metastatic MDA-MB-231 breast cancer cells. In order to examine whether Saussurea lappa Clarke suppresses cell growth inducing apoptosis cell death or cell cycle arrest, we analyzed DNA contents and cell cycle distribution using a flow cytometer and western blotting in MDA-MB-231 cells. We suggest that Saussurea lappa Clarke dose not induced apoptosis and induced G2/M phase cell cycle arrest. Moreover, Saussurea lappa Clarke also decreased the expression level of metastasis-angiogenesis releated protein such as VEGF. However, dose not changed the expression level of metastasis related protease MMP-1 in highly-metastatic MDA-MB-231 breast cancer cells. Therefore, Saussurea lappa Clarke might be good and useful chemotherapy agent highly-metastatic breast cancer patients.

The Understanding of Scientific Concept based on the 6th Graders' levels of Logical Thinking in Elementary School (논리적 사고력 수준에 따른 초등학교 6학년 학생의 과학적 개념의 이해 분석)

  • Kang, Cheol-Ung;Kim, Hyoung-Bum;Jeong, Jin-Woo
    • Journal of the Korean Society of Earth Science Education
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    • v.6 no.3
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    • pp.165-173
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    • 2013
  • This study was to analyse the understanding of the concepts of science based on the 6th graders' levels of logical thinking in elementary schools. To achieve the goal of this study, logical thinking test was given to 108 6th graders of elementary school and 32 students were interviewed. The result of this study was as follows. First, 61.1% of students were in concrete operational period in their logical thinking, 27.8% were in their transitional period, and 11.1% were in their formal operational period. By using Flow-Map, 32 students were analyzed and their levels of logical thinking was significantly associated with their understanding of concept. Students' flexibility of cognitive structure was significantly associated with logical thinking and the levels of understanding concepts as well. However, misconception didn't show significant association with levels of logical thinking. Second, the characters of understanding of scientific concept by their levels of logical thinking was that as you get higher levels of logical thinking, their cognitive structure to understand concept was more systemized, in order and more logical. The result of this study suggested the followings in science experiment class. First, 6th graders of elementary schools had various levels of logical thinking and that affected to their understanding of scientific concepts. Therefore, lesson planning and class should be done by reflecting their different levels of logical thinking. Second, since they had different levels of logical thinking, various teaching methods should be utilized to make students understand scientific concepts more systematically.

Large-scale structure of circular jet in transitional region at reynolds number of ${10}^{4}$ (Reynolds수 ${10}^{4}$일때 천이영역에서의 왼형제트의 Large-Scale 구조에 관한 연구)

  • 이택식;최은수
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.10 no.6
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    • pp.823-829
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    • 1986
  • The Large-scale structure of the circular jet in the transition region, which influences the subsequent flow in the turbulent region, was studied experimentally. Measuring equipments are composed of the two channel hot-wire anemometer, the computer controlled two-directional traverse mechanism, the data acquisition system, and FFT-analyzer. The circular jet has 50mm diameter. The mean velocity distribution, the velocity fluctuation, the auto 'cross correlations and the power spectra were acquired at moderate Reynolds number of 10$^{4}$. And the VITA method was used to measure the convection velocity of Large-scale eddy. The phase of u'is in advance of that of v'in all regions. .over bar. $R_{u}$(.tau.=0) is approximately zero in the potential core region, but a small regular deviation is observed. At a position in the mixing layer region the convection velocity is different along the part of the eddy, and in this experiment the convection velocity of the inner region is larger than the outer region. The averge convection velocity of the eddy along y/D=0 was approximately constant in the transition region.D=0 was approximately constant in the transition region.

A Study on Deep Geothermal Energy and Potential of Geothermal Power Generation in Mongolia (몽골의 심부 지열에너지 자원과 지열발전에 관한 연구)

  • Hahn, Jeong-Sang;Yoon, Yun-Sang;Kiem, Young-Seek;Hahn, Chan;Park, Yu-Chul;Mok, Jong-Gu
    • Journal of the Korean Society for Geothermal and Hydrothermal Energy
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    • v.8 no.3
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    • pp.1-11
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    • 2012
  • Mongolia has three(3) geothermal zones and eight(8) hydrogeothermal systems/regions that are, fold-fault platform/uplift zone, concave-largest subsidence zone, and mixed intermediate-transitional zone. Average temperature, heat flow, and geothermal gradient of hot springs in Arhangai located to fold-fault platform/uplift zone are $55.8^{\circ}C$, 60~110 mW/m2 and $35{\sim}50^{\circ}C/km$ respectively and those of Khentii situated in same zone are $80.5^{\circ}C$, 40~50 mW/m2, and $35{\sim}50^{\circ}C/km$ separately. Temperature of hydrothermal water at depth of 3,000 m is expected to be about $173{\sim}213^{\circ}C$ based on average geothermal gradient of $35{\sim}50^{\circ}C/km$. Among eight systems, Arhangai and Khentii located in A type hydrothermal system, Khovsgol in B type, Mongol Altai plateau in C type, and Over Arhangai in D type are the most feasible areas to develop geothermal power generation by Enhanced Geothermal System (EGS). Potential electric power generation by EGS is estimated about 2,760 kW at Tsenher, 1,752 kW at Tsagaan Sum, 2,928 kW at Khujir, 2,190 kW at Baga Shargaljuut, and 7,125 kW at Shargaljuut.

A Study on Expression Visual of Metamorphosis Transition of Image Animation (영상애니메이션 트랜지션의 메타모포시스 시각 표현에 관한 연구)

  • Joo, Hae-Jeong;Kim, Chee-Yong
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2010.05a
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    • pp.347-350
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    • 2010
  • With the advent of new media era we are living in the world of motion picture image is not an exaggeration. With the development of the mass media with images and moments that passed the day feeling like part of it is communication. In this era a sensual and shapeable image more than the logical and realistic thinking may be passed. In the act of seeing a moving image, prior to linguistic and conceptual meaning, color and screen configuration delivery and formative element in the change they produce is first recognized. Particular kind of video animation having the narrative structure, this territory effect greatly. the film even more significant effect on the area and linking the image of the scene transitions in the scheme also features a simple means of natural communication functions are being expanded. These transitional effects provide visual pleasure from a simple transition traditional methods. And In terms of narrative functions performed to help a narrative flow of availability, visual representation should continue.

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Knowledge from recent investigations on sloshing motion in a liquid pool with solid particles for severe accident analyses of sodium-cooled fast reactor

  • Xu, Ruicong;Cheng, Songbai;Li, Shuo;Cheng, Hui
    • Nuclear Engineering and Technology
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    • v.54 no.2
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    • pp.589-600
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    • 2022
  • Investigations on the molten-pool sloshing behavior are of essential value for improving nuclear safety evaluation of Core Disruptive Accidents (CDA) that would be possibly encountered for Sodium-cooled Fast Reactors (SFR). This paper is aimed at synthesizing the knowledge from our recent studies on molten-pool sloshing behavior with solid particles conducted at the Sun Yat-sen University. To better visualize and clarify the mechanism and characteristics of sloshing induced by local Fuel-Coolant Interaction (FCI), experiments were performed with various parameters by injecting nitrogen gas into a 2-dimensional liquid pool with accumulated solid particles. It was confirmed that under different particle-bed conditions, three representative flow regimes (i.e. the bubble-impulsion dominant, transitional and bed-inertia dominant regimes) are identifiable. Aimed at predicting the regime transitions during sloshing process, a predictive empirical model along with a regime map was proposed on the basis of experiments using single-sized spherical solid particles, and then was extended for covering more complex particle conditions (e.g. non-spherical, mixed-sized and mixed-density spherical particle conditions). To obtain more comprehensive understandings and verify the applicability and reliability of the predictive model under more realistic conditions (e.g. large-scale 3-dimensional condition), further experimental and modeling studies are also being prepared under other more complicated actual conditions.

Effects of Surface Compaction Treatment on Soil Loss from Disturbed Bare Slopes under Simulated Rainfalls (인공강우 시 나지교란사면 토사유출에 미치는 다짐처리의 영향)

  • Park, Sang Deog;Shin, Seung Sook;Kim, Seon Jeong;Choi, Byoungkoo
    • Journal of Korea Water Resources Association
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    • v.46 no.5
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    • pp.559-568
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    • 2013
  • Surface compaction significantly impacts runoff and soil erosion under rainfall since it leads to changes of soil physical characteristics such as increase of bulk density and shear stress, change of microporosity, and decrease of hydraulic conductivity. This study addressed surface compaction effects on runoff and soil loss from bare and disturbed soils that are commonly distributed on construction sites. Thirty-six rainfall simulations from three replicates of each involving rainfall intensities (68.5 mm/hr, 95.6 mm/hr) and plot gradients ($5^{\circ}$, $12.5^{\circ}$, $20^{\circ}$) were conducted to measure runoff and soil loss for two different soil surface treatments (compacted surface, non-compacted surface). Compacted surface increased significantly soil bulk density and soil strength. However, the effect of surface treatments on runoff changed with rainfall intensity and plot gradient. Rainfall intensity and plot gradient had a positive effect on mean soil loss. In addition, the effect of surface treatments on soil loss responded differently with rainfall intensity and plot gradient. Compacted surfaces increased soil loss at gentle slope ($5^{\circ}$) while they decreased soil loss at steep slope ($20^{\circ}$). These results indicate that there exists transitional slope range ($10{\sim}15^{\circ}$) between gentle and steep slope by surface compaction effects on soil loss under disturbed bare soils and simulated rainfalls.

Geometric Characteristics of Landslides on Natural Terrain according to the Geological Condition (지질조건에 따른 자연사면 산사태의 기하학적 특성)

  • Kim, Kyeong-Su;Song, Young-Suk;Chae, Byung-Gon;Cho, Yong-Chan;Lee, Choon-Oh
    • The Journal of Engineering Geology
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    • v.17 no.1 s.50
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    • pp.75-87
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    • 2007
  • The recognitions of geometrical characteristics and occurrence conditions are very important to evaluate the land-slides in natural terrains. In this paper, the geometrical characteristics of landslides are analyzed according to a geo-logical condition in three landslides areas. The three landslides areas are classified to the geological condition. The three landslides areas are Jangheung, Sangju and Pohang. The geology of Jangheung area, Sangju area and Pohang area is gneiss, granite, and the tertiary sedimentary rock, respectively. During a heavy rainfall of $150{\sim}588mm$ in these areas, 1,582 landslides have occurred in 1998. The geometrical characteristics according to the geological condition analyzed from the investigation of these landslides. The frequency of landslide is high exceedingly above 90% of a slope attitude, while the frequency is very low below 70%. The frequency of landslide is high exceedingly between $26^{\circ}$ and $30^{\circ}$ of slope angle, while the frequency is very low below $20^{\circ}$. The size of the landslides is ranged from several tens to several hundreds The length is ranged from 5 m to 300 m, and the width is ranged from 3 m to 50 m. Also, the depth is less than 1 m. Therefore, the landslides in these areas have small width, long length and shallow depth. The type of the landslides is changed from transitional slide at the scarp to debris flow at the low part of slope.

A Systematic Approach Of Construction Management Based On Last Planner System And Its Implementation In The Construction Industry

  • Hussain, SM Abdul Mannan;Sekhar, Dr.T.Seshadri;Fatima, Asra
    • Journal of Construction Engineering and Project Management
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    • v.5 no.2
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    • pp.11-15
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    • 2015
  • The Last PlannerSystem (LPS) has been implemented on construction projects to increase work flow reliability, a precondition for project performance againstproductivity and progress targets. The LPS encompasses four tiers of planning processes:master scheduling, phase scheduling, lookahead planning, and commitment / weeklywork planning. This research highlights deficiencies in the current implementation of LPS including poor lookahead planning which results in poor linkage between weeklywork plans and the master schedule. This poor linkage undetermines the ability of theweekly work planning process to select for execution tasks that are critical to projectsuccess. As a result, percent plan complete (PPC) becomes a weak indicator of project progress. The purpose of this research is to improve lookahead planning (the bridgebetween weekly work planning and master scheduling), improve PPC, and improve theselection of tasks that are critical to project success by increasing the link betweenShould, Can, Will, and Did (components of the LPS), thereby rendering PPC a betterindicator of project progress. The research employs the case study research method to describe deficiencies inthe current implementation of the LPS and suggest guidelines for a better application ofLPS in general and lookahead planning in particular. It then introduces an analyticalsimulation model to analyze the lookahead planning process. This is done by examining the impact on PPC of increasing two lookahead planning performance metrics: tasksanticipated (TA) and tasks made ready (TMR). Finally, the research investigates theimportance of the lookahead planning functions: identification and removal ofconstraints, task breakdown, and operations design.The research findings confirm the positive impact of improving lookaheadplanning (i.e., TA and TMR) on PPC. It also recognizes the need to perform lookaheadplanning differently for three types of work involving different levels of uncertainty:stable work, medium uncertainty work, and highly emergent work.The research confirms the LPS rules for practice and specifically the need to planin greater detail as time gets closer to performing the work. It highlights the role of LPSas a production system that incorporates deliberate planning (predetermined andoptimized) and situated planning (flexible and adaptive). Finally, the research presents recommendations for production planningimprovements in three areas: process related, (suggesting guidelines for practice),technical, (highlighting issues with current software programs and advocating theinclusion of collaborative planning capability), and organizational improvements(suggesting transitional steps when applying the LPS).