• Journal of Korean Society of Disaster and Security
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• v.14 no.4
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• pp.47-60
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• 2021

Recently, as the occurrence frequency of sudden floods due to climate variability increased, the damage of aging chuteway slabs of spillway are on the rise. Accordingly, a wide array of field survey, hydraulic experiment and numerical simulation have been conducted to find the cause of damage on chuteway slabs. However, these studies generally reviewed the flow characteristics and distribution of pressure on chuteway slabs. Therefore the derivation of damage on chuteway slabs was relatively insufficient in the literature. In this study, the cavitation erosion and hydraulic jacking were assumed to be the causes of damage on chuteway slabs, and the phenomena were reproduced using 3D numerical models, FLOW-3D and COMSOL Multiphysics. In addition, the cavitation index was calculated and the von Mises stress by uplift pressure distribution was compared with tensile and bending strength of concrete to evaluate the possibility of cavitation erosion and hydraulic jacking. As a result of numerical simulation on cavitation erosion and hydraulic jacking under various flow conditions with complete opening gate, the cavitation index in the downstream of spillway was less than 0.3, and the von Mises stress on concrete was 4.6 to 5.0 MPa. When von Mises stress was compared with tensile and bending strength of concrete, the fatigue failure caused by continuous pressure fluctuation occurred on chuteway slabs. Therefore, the cavitation erosion and hydraulic jacking caused by high speed flow were one of the main causes of damage to the chuteway slabs in spillway. However, this study has limitations in that the various shape conditions of damage(cavity and crack) and flow conditions were not considered and Fluid-Structure Interaction (FSI) was not simulated. If these limitations are supplemented and reviewed, it is expected to derive more efficient utilization of the maintenance plan on spillway in the future.

• Korean Architects
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• no.12 s.344
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• pp.50-50
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• 1997

이번 지역건축을 기획하면서, 여러 가지 상념에 잠기게 되었다. 건축에서 지역성이 어느 정도 내재되어 있는지 살펴보고자 하는 것이 혹시 더욱 부정적 결과를 확인하는 것이라면 이를 확인할 필요가 있을지, 또 어떤 긍정적 결과를 확인할 수 있을지, 게다가 여러 개발도상국의 상황과 아시아의 건축적 진행을 보면서, 어쩌면 우리는 더욱 난감한 상황을 보게 될지도 모른다. "건축을 발전시켜온 어떤 민족도 각기 독자적 언어, 복장, 민속이 있는 것처럼, 그들이 좋아하는 형태를 발전시켜왔다. 19세기에 문화의 국경이 붕괴될 때까지 온 세계의 건축에는 지역고유의 형태와 디테일이 있었다. 그리고 어떠한 지역특유의 건물도 사람들의 창조력과 그 지역의 필요성의 결합에 의하여 태어난 아름다운 산물이었다. 그러나 현대 이집트에는 이집트 고유의 토착양식을 찾아볼 수가 없다. 바로 이집트인의 서명이 없다. 그것이 부자들의 집이건 가난한 자의 집이건 무성격하기는 마찬가지이며 이집트인의 자취란 사라져 버렸다."(하산 화티,1973년) 선진국은 스스로 산업혁명을 일으켰고, 이런 사회적 문화적 변동에 적응하기 위하여 1세기 이상의 시간적 여유가 있었다는 것이다. 개발도상국의 급속한 변화에는 건물도 변화의 수단으로 이용되었다는 것이다. "민족적이며, 지역적인 전통이야말로, 새로운 지역주의의 기초로서 보존하고 사용되어야 된다는 '섬세한' 서양의 관찰자들의 탄원은 이같은 상황에서는 전연 고려되지 않았다."고 커티스는 보았다. 섬세한 서양인이 아니라 자국민 스스로 자신의 문명에 대하여 파괴적인 입장에 서 있다면 더욱 난감한 일이다. 지역주의의 의미는 무엇일까? 건축에서 '지역'의 범주는 어디인가? 인종적 분포 또는 민족적 무리를 이름지은 것인가? 아니면 인종과 민족의 공통점인가? 그것도 아니라면 정치적 경계선으로 둘러싸인 경계를 말하는 것인가? 모든 지역이 다 지역주의로 대별될 수 있는가? 어느 곳이 건축에서의 중심지역이며, 또 지역주의는 누가 판별하는가? 프램튼은 문화적인 중심지와 종속적 관계를 지니는 지역주의를 잘못된 구조로 보았다. 근래 10년간 세계적으로 다양한 지역주의가 대두했다. 지역의 개념적, 제도적, 법적인 상태가 어떠한가가 중요한 요인이 된다. 19세기 동안에 유럽사람들이 그들의 정치적 독립을 위한 목적에 활용하기 위하여 부분적으로 거짓된 역사관을 피력했을 때, 유럽지역에서의 지역주의 개념들은 아이리쉬, 까딸로니아, 핀랜드 등을 평가하는 역할이 있었다고 한다. 지역주의를 "감상적인 민족적 편견에서 비롯된 광신적 배타주의"라고 낮추어 바라보는 그로피우스의 시각에 대해, 당당히 맞설 수 있어야 할 것이다. 리꾀르의 말대로 미래에 어떠한 유형의 참된 문화를 유지하는 것은 궁극적으로는 문화나 문명의 단계에서 외래의 영향을 적절하게 하면서 지역문화의 활기찬 형태를 발생시키는 우리 능력에 달려있다. '지역적' 범위는 서구에서 합중국으로 존재하는 경우, 대부분 이질적 문화들의 혼합지역이기 때문이다. 한국과 같이 비교적 단일한 성분의 종족으로 한 국가가 유지된 경우와 미국과 같이 다양한 종족이 모인 경우 등과 비교하면 '지역'이란 이름에 어떤 판단기준이 있어야 할까? 근래 지역적 변동이 적었던 한국의 경우는 상대적으로 재론할 여지가 적다. 그러나 한국의 역사시대 내에서도 확인되지 않은 부분들이 존재하고, 역사시대의 범위를 넘어서 선사시대로 확대하면 '지역'의 개념의 외연적 대상은 더욱 모호해진다.

• Journal of the Earthquake Engineering Society of Korea
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• v.13 no.6
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• pp.87-98
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• 2009

It is well known that reinforcement details in the plastic hinge region of bridge piers give the most important effects on the seismic performance of bridges, from investigations of bridge failures in many earthquake events and in laboratory tests. Longitudinal reinforcement details give larger effects than lateral reinforcement details do. The lap-spliced longitudinal steel shows slip during earthquake events, which results in low ductility and inadequate seismic performance. However, before the issue of the earthquake design code, a considerable number of bridge piers were constructed with lap-spliced longitudinal steel in the plastic hinge region. Therefore, a large amount of research has been conducted on the seismic performance and retrofit of circular and rectangular shaped bridge columns with lap-spliced longitudinal steel. However, research on wall type piers is very limited. This paper investigates the seismic performance of a pier wall by a quasi-static test in the weak axis direction and proposes a retrofit method. From the test with variables being the longitudinal steel detail and the transverse steel amount, it is shown that the currently used definition of yield displacement is not adequate. Therefore a new definition of yield displacement for the ductility investigation for a pier wall is proposed. In addition, a retrofit method by steel plates and bolts is proposed to improve ductility, and test results show that slip of the longitudinal steel is prevented by up to a considerably large displacement.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.40 no.1
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• pp.97-103
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• 2020

The newly improved multistep steel pipe grouting method was applied to an existing steel pipe-reinforced grouting method. It was applied in order to prevent a damage caused by ground failure from excessive grouting pressure in a tunnel construction. The tunnel goes under a highway and a ramp connected to a rest area on OO highway with 11.3~12.1 m depth cover and is a part of roadbed facility construction section ordered by OO public corporation. The improved grouting method provides pre-construction work condition assessment technique through new water injection limit test and grouting effect assessment technique by grouting type assessment. It also includes assessments on interval of joints, appropriate grouting pressure, and optimal operation time to be applied to current operations. Application of the grouting method allowed the smooth road management in shallow-depth grouting construction area located upper part of tunnel excavation. Moreover, the possibility of the application of the method not only to shallow-depth grouting construction but also to various steel pipe-reinforced grouting constructions was confirmed.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.6
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• pp.92-98
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• 2019

In this study, we developed a repair material incorporating PVA powder resin and nylon fiber into cemented carbide used in the existing field to improve adhesion performance and water tightness with existing concrete. Flexural behavior evaluation was performed. The main experimental variables were PVA powder resin, nylon fiber mixing rate and damage type, and performance tests were conducted to evaluate compressive strength and flexural behavior after repairing materials. It was found that all formulations fully satisfied the required performance of the repair material. The flexural strength test results of the repaired tube specimens showed that the performance of the repaired materials was maximized when the nylon fiber was added and the PVA powder was added in an appropriate amount. The flexural behavior of all the specimens showed the flexural behavior of the structural members with a low rebar ratio, suggesting that the amount of iron wire in the domestic fume pipe was somewhat insufficient. That is, it was confirmed that the amount of reinforcement of the steel wire was somewhat small, so that the concrete was cracked before the behavior of the concrete and the steel wire reached the extreme state, and the concrete was immediately destroyed beyond the tensile strength of the concrete.

• Journal of the Korea Concrete Institute
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• v.19 no.5
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• pp.569-575
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• 2007

The repair of concrete surfaces does not normally take into account structural tolerance for longer service lift and better capabilities of concrete structures. In particular, the repair of surface spelling completes as mortar is applied, which does not display additional structural performances. The use of crimped wire mesh for better construction and fracture resistance, however, expects to have some reinforcement effects. Particularly, it is also expected that the repair of bottom part in structures built between bridges like irrigation structures results in the increase of flexural resistance. Therefore, this study is intended to perform the repair using crimp wire mesh and examine strength depending on the repair section and depth. For this, a slab with 150 mm in depth, 3,000 mm in length and 600 mm in width and total 8 objects to experiment such as upper part, upper whole, bottom part, bottom whole and crimp wire mesh reinforced are manufactured to perform flexural performance. The results of the analysis show that yield strength and failure load increase as the depth of repair materials in the experiment reinforced with crimp wire mesh get bigger. In the same condition, repair of bottom part is able to increase internal force of bending force. Besides, the results show that partial repair of structures under bending force cannot produce flexural performance. Consequently, the repair method with crimp wire mesh results in the increase of flexural resistance.

• 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.

• Cartoon and Animation Studies
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• s.42
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• pp.1-24
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• 2016

The 'fear' in animation has a couple of problems to apply the criteria for identical genre as in movie or literature. First, the mutilation and destruction of one's body and the appearance of monsters and ghosts are not a normal way of expression and could not apply to one genre. Second, the cause of fear comes from the subject of fear which is a reality that is something 'unrealistic' and 'special' and is approachable. This is all possible in a three dimensional world, but animation is not founded on realism. According to this logic, the horror genre in animation or the esthetic experience of animation is not possible. However, many of the powerful images you can see from the horror genre are all created from animation. Therefore, many writers are drawn to the horror in animation and tried to express in many different ways. This study will include the general idea of fear which drives the audience to the felling of fear and terror but we will mainly focus on the three types of fear - ghost story, cannibalism, and madness - and discover the meaning of fear used in animation. Through this process, we anticipate that fear in animation is not just for pure amusement, but will be able to investigate the meaning of fear philosophically even if the hidden side of reality is terrifying.

• Journal of fish pathology
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• v.7 no.2
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• pp.151-160
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• 1994

In order to elucidate the patterns of tissue damage evoked by the scuticociliatids, eighteen fingerlings of Japanese flounder, Paralichthys olivaceus, heavily infected with an unidentified scuticociliatid were histopathologically examined. Skin layer with the underlying musculature were severely necrotized due to the infestation of the ciliates. However in the early lesions, both dermis and myofibres remained relatively intact compared with other surrounding loose connective tissues. Mild damages were found in more dense tissues. One or more scuticociliatids were recognized in the blood and lymph vessels of the loose connective tissues with or without destructive changes. Many of nerve trunks or ganglia were also parasitized with less marked histological damage in the parenchyma. Dura and its adjacent tissues in the spinal cord were severely necrotized with massive accumulation of the ciliates in subdural space. The parasitic invasion in the central nervous system was usually confined to the cortical region. In the gill, variable degenerative changes were occurred due to the invasion of the ciliates recognized in the blood vessels of branchial arches or primary filaments. From these results, it was strongly suggested that the scuticociliatids are very actively penetrated into the deep tissues mainly through the severe destruction of the loose connective tissue components and that the vascular system could play a role in the rapid distribution of the ciliates to the remote tissues or organs.

• Asian Journal of Turfgrass Science
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• v.25 no.2
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• pp.133-137
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• 2011

Winterkill can be defined as any injury including freeze stress kill, winter desiccation, and low temperature disease to turfgrass plants that occurs during the winter period. The major damages from winterkill were low temperature kill, crown hydration, and winter desiccation. Low temperature kill is caused by air and soil temperature. Soil temperature affect more severe to turfgrass than air temperature because low soil temperature cause fetal damage to turfgrass crown. Crown hydration is a form of winter injury in which intercellular water within the plant freezes and causes physical injury to the cell membrane and wall. This is eventually resulted in dehydration of cell. Winter desiccation is the death of leaves or whole plants due to drought during the winter period. To reduce winterkill damage, cultivar selection is very important. If changing cultivar is not allowed, cold temperature hardiness needs to be increased by providing nutrients especially phosphorus and potassium in the late fall. Turf cover is effective way to reduce winterkill damage. Remaining snow is positive process to reduce winterkill damage by insulating soil temperature. The previous researches reported many materials as turf cover such as straw, polypropylene, polyester, and wood mat. Aeration and topdressing is one of the process against winterkill. Both methods are mainly conducted to reduce thickness of thatch layer. In recent, relatively new materials called black or winter topdressing sand are used to protect soil temperature from low air temperature and thaw ice crystal that may remain in soil.