• Title/Summary/Keyword: Weak Slope

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A Study on the Byung-Su Jo's House in Yongyu Island (인천 용유도의 조병수가옥에 대한 연구)

  • Han, Jong-Koo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.8
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    • pp.332-337
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    • 2017
  • This study investigates the site and architectural space of Byung-Su Jo's traditional house on Yongyu Island in Incheon. The house is located on a peaceful, warm site that is well protected by surrounding mountains, such as Hyunmubong to the rear, Jwacheongyong to the left, Wubackho to the right, and Ansan in front. The house was designed with an open layout with a sarangchae and anchae. There is a spring on the left side of the sarangchae, and a stream auspiciously flows from the west to the east in front of the sarangmadang. The house generally faces south, but to avoid pressure by the height of Ansan in the south direction, it is slightly turned to the east. There is a wide, rectangular pond that covers the pungsu weak point of the empty open view between the right and left mountains. The sarangchae space is composed of front 6 Gan and side 3 Gan. The anchae space is also composed of front 6 Gan and side 3 Gan,and it has a typical L-shaped anchae layout for the middle region of Korea. There is no shrine in the backyard, where yongmag is descending from hyunmubong, and a jangdokdae is installed to the west direction of the anbang due to narrow and slope backyard space.

Paleoenvironmental Reconstruction of the Hupo Basin Using Grain Size and Mineral Analysis (동해 후포분지 퇴적물의 입도와 광물 분석을 통한 고환경 해석)

  • Jun, Chang-Pyo;Kim, Chang-Hwan;Kim, Yeongkyoo;Lee, Seong-Joo
    • Journal of the Mineralogical Society of Korea
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    • v.27 no.3
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    • pp.159-168
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    • 2014
  • Holocene plaeoenvironmental changes were interpreted by grain size and mineral analyses of a piston core (HB 13-2), obtained along the western slope of the Hupo Basin, Korea. The core sediments are characterized by two discrete, sedimentary facies: upper unit (0-0.4 mbsf) dominated by bioturbation structures with weak lamination, and lower unit (0.4-3.3 mbsf) characterized by intensified bioturbation toward bottom. Analysis of sensitive grain size and sortable silt demonstrated that the inflow of the Tsushima Warm Current (TWC) into the Hupo Basin strengthen from the period of sediment deposition over 0.82 mbsf. The minerals of the core sediments are composed mainly of quartz, microcline, orthoclase, albite and clay minerals including chlorite, kaolinite and illite. No noticeable changes of the mineral percentage was observed according to the grain size and depth of the samples. The integral breadth (${\Delta}^{\circ}2{\theta}$) of clay minerals from 1.4 mbsf to top layer shows an increasing trend, which clearly means climate warming from the period of sediment deposition above 1.4 mbsf. This interval correlates with the Holocene climate optimum at Mid Holocene.

The Post Occupancy Evaluation of the Universal Design Project on Geonjisan Forest Trail Jeonju City, South Korea (전주시 건지산 숲길 Universal Design 사업 이용후 평가)

  • Park, Sun-A;Lee, Myung-Woo
    • Journal of the Korean Institute of Landscape Architecture
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    • v.40 no.6
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    • pp.60-69
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    • 2012
  • The project on Geonjisan Universal Design Forest Trail in Jeonju City was designed and constructed by an NGO called 'Jeonbuk Forest for Life' which was a winner for the '2008 Open Competition by the 'Committee for Greening Society' established in Korea Land Corporation. The purpose of this study is to evaluate the design satisfaction of UD forest trail. Post Occupancy Evaluation (POE) method was applied to measure the user satisfaction and the total number of users. The main result of the study were as follows: the major users of the Geonjisan UD forest trail were people aged over 60 years old(37%) and the main purpose of trail usage were to 'walk and rest'(51.5%) and to 'exercise and rehabilitation' (40.6%). Furthermore, the overall user rating for the UD forest trail design was "satisfied"(3.91 point in 5-point Likert Scale). The three most influencing factors of the overall user satisfaction were facility management, user conflict, and trail width and slope. About forty-five people were found to be End-user in the UD forest trail while six people were found as End-user in non-UD trails. Most importantly, the number of End-user observed on the UD forest trail was greater than the number found in non-UD forest trail. The result implies that the UD forest trail attracts more End-users and provides opportunity for gathering and interaction with the other users. Moreover, the satisfaction rate for the UD forest trail landscape is found to be high in Likert scale, which we can assume that the well-grown existing trees and topographic features as well as appropriately designed wood-paths influence the high satisfaction rate of the users. The POE of UD forest trail revealed the importance of universal design concept due to its convenient uses of the handicapped, old, weak, pregnant woman or children.

A Study on Stability of Levee Revetment in Meandering Channel (만곡수로 내의 호안 안정성 연구)

  • Kim, Sooyoung;Yoon, Kwang Seok;Kim, Hyung-Jun
    • Journal of Korea Water Resources Association
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    • v.48 no.12
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    • pp.1077-1087
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    • 2015
  • The levee protect lifes, houses, and properties by blocking overflow of river. The revetment is forced to be covered on the slope of levee in order to prevent erosion. The stability of revetment is very important enough to directly connected to the stability of levee. In this study, the weak points of revetment on meandering channel were found by movable revetment experiment and the velocity and the water surface elevation (WSE) were measured at main points. The 3-D numerical simulations were performed under same conditions with experiment. And unclear flow characteristics by the limit of measuring instruments were analyzed through numerical simulation. Consequently, the section of large wall shear stress and the failure section are almost the same. Despite of small wall shear stress, the revetments located at right bank were carried away because of circulation zone due to secondary flow by meandering. With existing riprap design formula, the sizes of riprap determined using maximum local velocity were 1.5~4.7 times greater than them using mean velocity. As a result of this study, it is necessary to calculate the size of riprap in other ways for meandering and straight channel. At a later study, if the weighted value considered the radius of curvature and shape of hydraulic structure is applied to riprap design formula, it is expected that the size of revetment was evaluated rationally and accurately.

Geomorphic Processes of Masung Basin (마성분지(麻城盆地)의 지형생성작용(地形生成作用))

  • Son, Myoung-Won
    • Journal of the Korean association of regional geographers
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    • v.2 no.1
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    • pp.39-49
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    • 1996
  • There is a limestone basin surrounded by the mountains consisted of Paleozoic sedimentary and metamorphic rocks in the Masung, Munkyung city, Kyungsangpook do. The purpose of this paper is to elucidate the geomorphic processes of the gentle hillslopes in the marginal piedmont of Masung basin. To do so, I analyzed deposits over hillslopes and the relation ship between the distance from the divide and the height(above sea level) at the longitudinal profile of the hillslope, and considered interrelation between the distributions of the gentle hillslopes(less than 230m) and lithology. Geomorphic processes of Masung basin are as follow: (1) The depth of deposits over hillslope increases toward downstream of the hillslope. Most gravels within deposits, whose lithology is limestone, are those eroded at the boundary(overthrust fault zone) between the back-mountain and the hillslope. Deposits at the outward margin of hillslope is well sorted. and moderately imbricated. (2) Hillslope at the margin of the basin(160-230m asl) is formed by the action of 'the flow with channel'. At the boundary between the soft rock(limestone; basin floor) and hard rock(sedimentary and metamorphic rock; back-mountain), the relatively weak limestone is eroded to fresh bedrock by the subsequent action of the overland flow, and therefore discontinuity in slope appeared. (3) After hills lopes were formed, sediments(boulders and fine material) produced during dissection in back-mountain buried deposits over hillslope. In conclusion, geomorphic processes of Masung basin is 'differential erosion due to differentiation of lithological hardness' having suggested as geomorphic processes of granitic basin. However it is not 'removal of weathering material due to sheetflow' but 'erosion due to the overland flow with channel'.

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Evaluation of the Stability of Geomembrane Liner System in Closed Waste Landfill (사용종료 폐기물 매립장의 멤브레인 차수시스템 안정성 평가)

  • Lee, Heung-Gil;Oh, Young-In
    • Journal of the Korean Geosynthetics Society
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    • v.9 no.1
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    • pp.39-46
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    • 2010
  • Recently, the effective use of closed waste landfill nearby urban areas has been demanded, because of the lack of the usable land. However, the reuse of closed landfill is needed an adequate stabilization of liner system. But most of these places are consisted of steep slope and hence it is necessary to use the geosynthetics liners in there. Liner system of waste landfills is an important facility which prevents leachate outgoing from the landfills and also groundwater infiltrating from surroundings into the landfills. During the waste disposal stage, differential settlement and tensile stress of the geosynthetic materials could occur due to impact load of trucks and dozers, waste loads and weak foundation soils. In this study, the tensile strength and tracer test were performed to evaluate the stability of geomembrane liner systems. Based on the tensile strength test result of in-situ geomembrane sample, the yield tensile strength maintain the suitable strength by specification and current law. However, according to the tracer test, the damage of geomembrane liner was detected on sanitary landfill section.

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Design of the Power Assist Controller for the In-Wheel Type Smart Wheelchair (인휠형 스마트 휠체어를 위한 힘 보조 제어기 설계)

  • Kong, Jung-Shik;Baek, Seung-Yub
    • Journal of the Korean Institute of Intelligent Systems
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    • v.21 no.1
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    • pp.80-85
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    • 2011
  • This paper presents the design of the power-assisted controller for the in-wheel type smart wheelchair by using torque estimation that is predicted by relationship between input voltage and output wheel angular velocity. Nowadays, interest of the moving assistant aids is increased according to the increase in population of the elderly and the handicapped person. However some of the moving assistant aids have problems. For example, manual wheelchair has difficulty moving at the slope, because users lack the muscular strength of their arm. In electric wheelchair case, users should be weak by being decreased muscles of upper body. To overcome these problems, power-assisted electric wheelchair are proposed. Most of the power-assisted electric wheelchair have the special rims that can measure the user's power. In here, the rims have to be designed to install the sensors to measure user's power. In this paper, we don't design the rim to measure the man power. To predict the man power, we propose a control algorithm of the in-wheeled electric wheelchair by using torque estimation from the wheel. First, we measure the wheel velocity and voltage at the in-wheel electric wheelchair. And then we extract driving will forces by using proposed mathematical model. Also they are applied at the controller as the control input, we verify to be able to control in-wheel type smart wheelchair by using simulation.

Comparison of Inodilator Effect of Higenamine, YS49, YS51, Tetrahydroisoquinoline Analogs, and Dobutamine in the Rat

  • Chong, Won-Seog;Lee, Young-Soo;Kang, Young-Jin;Lee, Duck-Hyung;Ryu, Jae-Chun;Yun-Choi, Hye-Sook;Chang, Ki-Churl
    • The Korean Journal of Physiology and Pharmacology
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    • v.2 no.3
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    • pp.323-330
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    • 1998
  • Tetrahydroisoquinoline (THI) alkaloids can be considered as cyclized derivatives of simple phenylethylamines. Many of them, especially with 6,7-disubstitution, demonstrate a relatively high affinity for catecholamines. Present study examines the pharmacological action of limited series of THI, using rats' isolated atria and aorta. In addition, a $[^3H]$ prazosin displacement binding study with THI compounds was performed, using rat brain homogenates to investigate whether these probes have ?${\alpha}$-adrenoceptor affinity. We also compared the vascular relaxation potency of these probes with dobutamine. YS 49, YS 51, higenamine and dobutamine, concentration-dependently, relaxed endothelium-denuded rat thoracic aorta precontracted with phenylephrine (PE, 0.1 ${\mu}M$) in which $pEC_{50}$ were $5.56{\pm}0.32$ and $5.55{\pm}0.21$, $5.99{\pm}1.16$ and $5.57{\pm}0.34$, respectively. These probes except higenamine also relaxed KCl (65.4 mM)-contracted aorta. In isolated rat atria, all THIs and dobutamine increased heart rate and contractile force. In the presence of propranolol, the concentration response curves of YS 49 and YS 51 shifted to the right and resulted in $pA_2$ values of $8.07{\pm}0.84$ and $7.93{\pm}0.11$, respectively. The slope of each compound was not deviated from unity, indicating that these chemicals are highly competitive at the cardiac ?${\beta}-adrenoceptors$. YS 49, YS 51, and higenamine showed ?${\alpha)-adrenoceptor$ affinity in rat brain, in which the dissociation constant $(K_i)$ was 2.75, 2.81, and 1.02 ${\mu}M$, respectively. It is concluded, therefore, that THI alkaloids have weak affinity to ${\alpha)_1-adrenoceptor$ in rat aorta and brain, respectively, while these probes show relatively high affinity for cardiac ${\beta}-adrenoceptors$. Thus, these chemicals may be useful in the treatment of congestive heart failure.

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Effects of Adenosine on the Action Potentials of Rabbit SA Nodal Cells (동방결절 활동전압에 대한 아데노신 효과)

  • Kim, Ki-Whan;Ho, Won-Kyung
    • The Korean Journal of Physiology
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    • v.18 no.1
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    • pp.19-35
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    • 1984
  • Since the first report of Drury and $Szent-Gy{\ddot{o}}rgyi$ in 1929, the inhibitory influences of adenosine on the heart have repeatedly been described by many investigators. These studies have shown that adenosine and adenine nucleotides have overall depressant effects, similar to those of acetylcholine. Heart beats become slow and weak. It is also well known that adenosine is a potent endogenous coronary vasodilator. Many investigations on the working mechanisms of adenosine have been focused mainly on the effects of the coronary blood flow. However, the cellular mechanisms underlying the inhibitory action of adenosine on sinus node are not well understood yet. Thus, this study was undertaken to examine the behavior of rabbit SA node under influence of adenosine. In these series of experiments three kinds of preparations were used: whole atrial pair, left atrial strip, and isolated SA node preparations. The electrical activity of SA node was recorded with conventional glass microelectrodes 30 to 50 $M{\Omega}$. The preparations were superfused with bicarbonate-buffered Tyrode solution of pH 7.35 and aerated with a gas mixture of $3%\;CO_2-97%\;O_2$ at $35^{\circ}C$. In whole atrial pair, adenosine suppressed sinoatrial rhythm in a dose-dependent manner. Effect of adenosine on atrial rate appeared at the concentration of $10^{-5}M$ and was enhanced in parallel with the increase in adenosine concentration. Inhibitory action of adenosine on pacemaker activity was more prominent in the preparation pretreated with norepinephrine, which can steepen the slope of pacemaker potential by increasing permeability of $Ca^{+2}$. Calcium ions in perfusate slowly produced a marked change in sinoatrial rhythm. Elevation of the calcium concentration from 0.3 to 8 mM increased the atrial rate from 132 to 174 beats/min, but over 10 mM $Ca^{+2}$ decreased. The inhibitory effect of adenosine on sinoatrial rhythm developed very rapidly. Atrial rate was recovered promptly from the adenosine-induced suppression by the addition of norepinephrine, but extra $Ca^{+2}$ was less suitable to restore the suppression of atrial rate. Adenosine suppressed also atrial contractility in the same dosage range that restricted pacemaker activity, even in the reserpinized preparation. In isolated SA node preparation, spontaneous firing rate of SA node at $35^{\circ}C$(mean{\pm}SEM, n=16) was $154{\pm}3.3\;beats/min. The parameters of action potentials were: maximum diastolic potential(MDP), $-73{\pm}1.7\;mV: overshoot(OS), $9{\pm}1.4\;mV: slope of pacemaker potential(SPP), $94{\pm}3.0\;mV/sec. Adenosine suppressed the firing rate of SA node in a dose-dependent manner. This inhibitory effect appeared at the concentration of $10^{-6}M$ and was in parallel with the increase in adenosine concentration. Changes in action potential by adenosine were dose-dependent increase of MDP and decrease of SPP until $10^{-4}M$. Above this concentration, however, the amplitude of action potential decreased markedly due to the simultaneous decrease of both MDP and OS. All these effects of adenosine were not affected by pretreatment of atropine and propranolol. Lowering extra $Ca^{2+}$ irom 2 mM to 0.3 mM resulted in a marked decrease of OS and SPP, but almost no change of MDP. However, increase of perfusate $Ca^{2+}$ from 2 mM to 6 or 8 mM produced a prominent decrease of MDP and a slight increase of OS and SPP. Dipyridamole(DPM), which is known to block the adenosine transport across the cell membrane, definately potentiated the action of adenosine. The results of this experiment suggest that adenosine suppressed pacemaker activity and atrial contractility simultaneously and directly, by decreasing $Ca^{2+}-permeability$ of nodal and atrial cell membranes.

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Site Characterization using Shear-Wave Velocities Inverted from Rayleigh-Wave Dispersion in Chuncheon, Korea (레일리파 분산을 역산하여 구한 횡파속도를 이용한 춘천시의 부지특성)

  • Jung, JinHoon;Kim, Ki Young
    • Geophysics and Geophysical Exploration
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    • v.17 no.1
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    • pp.1-10
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    • 2014
  • To reveal and classify site characteristics in densely populated areas in Chuncheon, Korea, Rayleigh-waves were recorded at 50 sites including four sites in the forest area using four 1-Hz velocity sensors and 24 4.5-Hz vertical geophones during the period of January 2011 to May 2013. Dispersion curves of the Rayleigh waves obtained by the extended spatial autocorrelation method were inverted to derive shear-wave velocity ($v_s$) models comprising 40 horizontal layers of 1-m thickness. Depths to weathered rocks ($D_b$), shear wave velocities of these basement rocks ($v_s^b$), average velocities of the overburden layer ($\bar{v}_s^s$), and the average velocity to a depth of 30 m ($v_s30$), were then derived from those models. The estimated values of $D_b$, $v_s^b$, $\bar{v}_s^s$, and $v_s30$ for 46 sites at lower altitudes were in the ranges of 5 to 29 m, 404 to 561 m/s, 208 to 375 ms/s, and 226 to 583 m/s, respectively. According to the Korean building code for seismic design, the estimated $v_s30$ indicates that the lower altitude areas in Chuncheon are classified as $S_C$ (very dense soil and soft rock) or $S_D$ (stiff soil). To determine adequate proxies for $v_s30$, we compared the computed values with land cover, lithology, topographic slope, and surface elevation at each of the measurement sites. Due to a weak correlation (r = 0.41) between $v_s30$ and elevation, the best proxy of them, applications of this proxy to Chuncheon of a relatively small area seem to be limited.