• Research in Plant Disease
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• v.9 no.3
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• pp.159-161
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• 2003

Leaf spot diseases were found on safflower (Carthamus thinctorius) leaf in several fields located in Euisong-Gun, Gyengbuk province in Korea. The infected leaf rate of the diseases in surveyed area were different each years from 2001 to 2003 such as about 5%, 10%, and 30%, repectively. The typicla symptoms of diseases appeared first as small, light brown spots on leaves. And then spot turn dark brown and magnified. And yellow decoloration zone appeared surrounding dark brown spots. Mycological characteristics of Alternaria carthami, isolated from safflower mature leaf spot were dark gray colonies, conidiophores simple erect, septated, 40~80 ${\mu}m$ length; conidia solitary, straight, body size fo without beak length 40~100${\mu}m$, 10~15${\mu}m$ thick, Number of transverse septa 4~10 and longitudinal septa 4~7 ; beak with 2~4 septa, 30~65${\mu}m$ length. And A. alternata, isolated from old leaf were gray~dark gray colonies, conidiophores simple or branched, 20~110 ${\mu}m$ length; conidia long chaines, short conical or cylindrical beak, 2~6 transverse septa and several longitudinal septa, body size of without beak length 30~60 ${\mu}m$, 10~20 ${\mu}m$ thick ; beak length 5~35 ${\mu}m$. These are the first report on the leaf spot of safflower caused by Alternaria carthami, A alternata in Korea.

• Journal of Korean Society of Steel Construction
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• v.15 no.1
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• pp.1-8
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• 2003

In locations where the cost of concrete is relatively high or in situations where the weight of concrete members has to be kept to a minimum, it may be more economical to use hollow reinforced concrete vertic al members. Hollow reinforced concrete colun-ms with a low axial load, a moderate longitudinal steel percentage and a reasonably thick wall were found to perform in a ductile manner at the flexural strength, similar to solid columns. Hollow reinforced concrete columns with a high axial load, a high longitudinal steel percentage, and a thin wall were found, however, to behave in a brittle manner at the flexural strength, since the neutral axis is forced to occur away from the inside face of the tube towards the section centroid and, as a result, crushing of concrete occurs near the unconfined inside face of the section. If, however, a steel tube is placed near the inside face of a circular hollow column, the column can be expected not to fail in a brittle manner through the disintegration of the concrete in the compression zone. A design recommendation and example through the moment-curvature analysis program for curvature ductility are herein presented. A theoretical moment-curvature analysis for reinforced concrete columns, indicating the available flexural strength and ductility, can be conducted, providing that the stress-strain relation for the concrete and steel are known. In this paper, a unified stress-stain model for confined concrete by Mander is developed foi members with circular sections.

• Tunnel and Underground Space
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• v.16 no.6 s.65
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• pp.526-535
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• 2006

An experimental study was carried out on a reduced scale tunnel model to grasp the behavioral feature of fire-induced smoke in the long tunnels. Based on Froude modeling, the 1/50 scaled tunnel model (20 m long) was constructed by acrylic tubes and paraffin gas was released inside the tunnel to simulate the 20 MW fire-induced smoke. me test results show, that after approximately 2 minutes of fire generation, was descended from the tunnel ceiling through the decrease of buoyancy, then it was symmetrically propagated about 90 meters for 4 minutes before jet fans were operated. The smoke was effectively controlled when the jet fans were operated and an air stream velocity was getting closed to reach a critical velocity (the minimum air velocity that requires to suppress the smoke spreading against the longitudinal ventilation flow during the tunnel fire situations). It was also found out that a range of smoke was spreaded about 3 meters from the origin of fire but the range was not propagated to the escape direction anymore. The early stage of the In operation, however, showed that the smoke was hardly controlled. It means that the operation of emergency ventilation system has many dangerous factors such as an intercepting breathing zone.

• Korean Journal of Ecology and Environment
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• v.41 no.3
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• pp.301-310
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• 2008

This study was to analyze characteristics of fish compositions and longitudinal distribution, based on trophic and tolerance guild at 22 sampling sites of Yeongsan River watershed during 2003$\sim$2006, and also to compare before and after the estuary dam construction. The collected fishes, based on catch per unit effort (CPUE), were 44 species in the watershed and dominant fishes were Zacco platypus, Acheilognathus macropeterus, Zacco temminckii and Carassius auratus. According to comparative analysis of fish in the non polluted sites (NPS) vs. polluted sites (PS), the number of species and individuals was lower by 70% in the PS than the NPS, indicating ecological degradations by chemical pollutions or/and habitat modifications. The relative abundance of sensitive and insectivore species decreased as the stream order increases, while tolerant and omnivore species increased with the stream order. In this survey, largemouth bass (Micropterus salmoides), which is a top-carnivore and exotic species, may influence trophic guild system throughout active predations on endemic species, resulting in modifications of ecological functions. The construction of estuary dam on Yeongsan River in 1981 resulted in wider lacustrine zone and desalinated through limitation of seawater input. These physical changes have caused increases of lentic dwelling species and limited fish migrations (i.e., eel). Overall, fish fauna and composition analyses showed that the number of species and individuals in this water body may be reduced due to inputs of pollutants from the watershed, habitat modifications, and increases of exotic species (largemouth bass). For these reasons, effective lake management strategies are required for the ecosystem conservation.

• Journal of Korean Tunnelling and Underground Space Association
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• v.14 no.5
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• pp.529-545
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• 2012

Three-dimensional (3D) finite element analyses have been performed to study the behaviour of a single pile to open face tunnelling in stiff clay. Several key factors such as tunnelling-induced ground and pile settlement, and shear transfer mechanism have been studied in detail. Tunnelling resulted in the development of pile settlement larger than the Greenfield soil surface settlement. In addition, due to changes in the shear transfer between the pile and the soil next to the pile with tunnel advancement, axial force distributions along the pile change drastically. The apparent allowable pile capacity was reduced up to about 30% due to the development of tunnelling-induced pile head settlement. The skin friction on the pile was increased with tunnel advancement associated with the changes of soil stresses and ground deformation and hence axial pile force distribution was reduced. Maximum tunnelling-induced tensile force on the pile was about 21% of the designed pile capacity. The zone of influence on the pile behaviour in the longitudinal direction may be identified as ${\pm}1$-2D (D: tunnel diameter) from the pile centre (behind and ahead of the pile axis in the longitudinal direction) based on the analysis conditions assumed in the current study. Negative excess pore pressure was mobilised near the pile tip, while positive excess pore pressure was computed at the upper part of the pile. It has been found that the serviceability of a pile experiencing adjacent tunnelling is more affected by pile settlement than axial pile force changes.

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.1
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• pp.18-24
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• 2016

The purpose of this study is to induce the ductile behavior of the Ultra High Perfomance Concrete Reinforced I beam by substituting the part of steel fiber for bundle of reinforcing bars. Experiment of flexural behavior of the Ultra High Performance Concrete I shaped beam with the combination of the steel fiber and bundle of reinforcement bars was carried out. The volume fractions of steel fiber are 0%, 0.7%, 1%, 2%. The bundle of reinforcing bars and prestressing wire are used to restrain the concrete in compression zone. Length of bundle of reinforcing bar and prestressing wire is the one of test factors. The 9 Reinforced UHPC I shaped beam were made with these test factors. Not only steel fiber but also bundle of longitudinal reinforcing bar has effect to induce the ductile behavior of Reinforced UHPC I beam. The combination of 0.7% or 1.0% steel fiber and bundle of reinforcing bar showed the effective ductile behavior of I beam. The relationship of load-deflection and the crack pattern indicate the usefulness of the bundle of the longitudinal bar which has small diameter with close arrangement each other.

• Journal of the Korean Arthroscopy Society
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• v.6 no.2
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• pp.156-160
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• 2002

Purpose : To evaluate the results and usefulness of meniscal repair using meniscal arrows with ACL reconstruction. Material and Methods : Among cases of the simultaneous meniscal arrow fixation and ACL recontruction performed between May, 1997 and September, 2000, 17 cases could be evaluated. The average follow-up were 18.5 months. Twelve cases were medial meniscus, 5 cases, lateral meniscus. All cases were longitudinal tear. Meniscal tear were seen at red-red zone in 13 cases, red-white zone in 5 cases. The results were analyzed by pain, joint line tenderness, locking, McMurray test, the Marshall knee scoring scale and complications. Results : Postoperatively two patients had mild joint line tenderness without pain on joint motion or weight bearing. No patient had locking or positive McMurray test. At last follow-up, 15 cases $(88\%)$ were 'excellent' or 'good' according to the Marshall knee score scale. There were two complications which are soft tissue irritation sign on active knee motion and a femoral chondral injury due to protruded T-shaped head of meniscus arrow. Conclusion : Meniscus arrow can be one of the options in repairing the associated meniscus tear, especially the posterior horn of medial meniscus, during ACL reconstruction. However, surgeons using meniscus arrow should be aware of its potential complications such as pain due to soft tissue irritation and chondral damage of the femoral condyle.

• Journal of the Korean Arthroscopy Society
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• v.6 no.2
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• pp.150-155
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• 2002

Purpose : The purpose of this study was to evaluate the clinical results of meniscal repair using the bioabsorbable devices. Materials and Methods : From 1998, 21 meniscal repairs were underwent using the bioabsorbable devices and followed more than 1 year. The Meniscus $Arrow^{\circledR}$(Bionx) and the Meniscal $Fastener^{\circledR}$(Mitek) had been applied. The indication for meniscus refixation was an unstable longitudinal tear in the posterior horn of the medial or lateral meniscus. Concurrent ACL reconstruction with meniscal repair was performed on 9 knees. The clinical result was evaluated using Lysholm knee score. Result : The average Lysholm knee scores for all patients improved from 56 preoperatively, to 89 postoperatively. The type of the device were not significantly related to clinical outcome or Lysholm knee score. But the concurrent ACL reconstruction group and the patients treated within 8 weeks had better clinical result than the others. Conclusion : The all-inside meniscal repair technique using bioabsorbable devices can be considered to be an useful method in the well selected patients and concurrent ACL reconstruction surgery.

• Magazine of the Korea Concrete Institute
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• v.6 no.1
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• pp.120-130
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• 1994

The purpose of this study is to propose the analytical model for the hysteretic behavior of Reinforced Concrete bearn-column joints under various loading history. Discrete line elernents , YVith inelastic rotational spring was adopted to consider the movement of plastic hinging zone influenced by the details of longitudinal reinforcements. Also hysteretic model was constructed by excluding such variables which can not be utilized in dynamic analysis of Reinforced Concrete. structure that it will be adoptable in two-dimensional inelastic frame ardysis with 6-DOF. From the analysis of previous test results, it was found that stiffness deterioration caused by inelastic hysteretic loadings can be predicted by the functron of basic pinching coefficients, ductility ratio.and yield strength ratio of members. Strength degradation coefficients were newly proposed to explain the difference of inelastic behavior of members caused by spacing ratio of transverse steel and sectlon aspect ratio. The energy dissipation capacities calculated using the analytical model proposed in thls paper show a good agreements w~lh test results by an error of 10~20%.

• Geotechnical Engineering
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• v.1 no.2
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• pp.41-54
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• 1985

Generally, ground settlements and lateral displacements are accompanied by underground excavation associated with open-cut or tunnling. These ground movements cause a harmful influence upon nearby super.structures and sub-structures. Occasionally, the ground movements may pose serious problems as the function of the nearby structures may be disrupted. Therefore, prior to the subway construction in an urban area, it is necessary to identify the causes of ground settlements and estimating the extent St the magnitude of ground movements since any potential damage to the nearby structures such as gas lines, water mains, high buildings and cultural assets must be assessed. The research was performed mainly on ground movements such as surface settlements, lateral displacements, subsurface settlements and crown settlements to predict the maximum settlement and settlement zone, and to identify the causes of ground settlements in NATM sections of Busan subway. As a result, it was found that lateral distribution of settlements could be approximated reasonably by a Gaussian normal probability curve and longitudinal distribution of settlements by a cumulative Gaussian probability curve, and that the early closure of temporary invert was very important to minimize ground settlements.