• Title/Summary/Keyword: limit state

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Examination on unified Silla's cultural exchange and brick pagoda formation course (통일신라의 문화교류 및 전탑형성과정에 대한 고찰)

  • Kim, Sang-Gu;Lee, Jeong-Soo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.8
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    • pp.5369-5377
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    • 2014
  • Korean pagodas were constructed in the shape of a wood pagoda, brick pagoda, stone pagoda, etc. On the other hand, the currently remaining traditional pagodas are those having nonflammable materials, such as brick, stone, etc. Compared to the stone pagoda, there is data regarding brick pagodas, but there is little literature data on how to construct these pagodas. This appears to be because there are relatively few Korean brick pagodas currently remaining, they are locally restricted, the material limit is not overcome, pagoda's historical and regional problems have not been analyzed, and pagoda construction is centered on pagoda construction. Therefore, this study examined the local cultural characteristics on the construction of brick pagodas. As a result, cultural exchange between Korea and China was performed through the silk road and there was a marine route for cultural exchange. Such exchange was shared with the East Asia area as well, which can be found by comparing remains at related areas. Exchange with China can be mentioned as the selective exchange of local powers as well as blind learning. Second, brick pagoda were constructed in Korea because of the good quality soil easily. Uisang's Hwaeomjong was negotiated with the main power not agreeing with Buddhism, which was popularized and the local power. Third, brick pagoda construction was influenced by negotiation related between Balhae and Silla, in which the ethnic influence was locally affected and could be mentioned as being a culturally selective result transferred from China. As a result, brick pagodas can be oriented by forming a unitary state rather than a small country within China's influence range as well as cultural transfer through the silk road.

Alternative Policy and Actual State on Compensation for Fisheries Damage by Oil Pollution (유류 오염에 의한 어업피해 보상 실태와 대응 방안)

  • Jang, Duck-Jong
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.11 no.1 s.22
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    • pp.61-70
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    • 2005
  • The most likely influenced by the oil pollution at the sea is the fisheries industry, because if the destruction if the marine ecological system The rate if compensation for damage from IOPC Fund due to the incident if oil pollution is more or less $20\%$, which is remarkably lower than those cf our adjacent nations or European nations. The reason such a low rate cf compensation is that it is not easy to take evidences if changed caused by oil pollution requested by IOPC Fund due to the environments if our fisheries. Therefore unless the environments if our fisheries is changed completely, it is very difficult to get actual compensation for damages under the existing system, considering the results if the oil pollution damage compensation claim cases up to now. In this study tried to identify the actual benefits of 03FC convention that raises the upper limit if the compensation while keeping the criterion for compensation And proposed to supplement the compensation system of damage caused by oil pollution with analyzing the actual status if compensation from. IOPC Fund for the our oil pollution incidents and the judgment if Supreme Court on the case if oil. pollution acident in Keumdong No.5.

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Technique for the Measurement of Crack Widths at Notched / Unnotched Regions and Local Strains (콘크리트의 노치 및 비노치 구역에서의 균열폭 및 국부 변형률 정밀 측정기법)

  • Choi, Sok-Hwan;Lim, Bub-Mook;Oh, Chang-Kook;Joh, Chang-Bin
    • Journal of the Korea Concrete Institute
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    • v.24 no.2
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    • pp.205-214
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    • 2012
  • Crack widths play an important role in the serviceability limit state. When crack widths are controlled sufficiently, the reinforcement corrosion can be reduced using only existing concrete cover thickness due to low permeability in the region of finely distributed hair-cracks. Thus, the knowledge about the tensile crack opening is essential in designing more durable concrete structures. Therefore, numerous researches related to the topic have been performed. Nevertheless accurate measurement of a crack width is not a simple task due to several reasons such as unknown potential crack formation location and crack opening damaging strain gages. In order to overcome these difficulties and measure precise crack widths, a displacement measurement system was developed using digital image correlation. Accuracy calibration tests gave an average measurement error of 0.069 pixels and a standard deviation of 0.050 pixels. Direct tensile test was performed using ultra high performance concrete specimens. Crack widths at both notched and unnotched locations were measured and compared with clip-in gages at various loading steps to obtain crack opening profile. Tensile deformation characteristics of concrete were well visualized using displacement vectors and full-field displacement contour maps. The proposed technique made it possible to measure crack widths at arbitrary locations, which is difficult with conventional gages such as clip-in gages or displacement transducers.

The Effect of the Phytoncide in Decreasing the Mouth Odor (피톤치드의 입냄새 제거효과)

  • Park, Jae-Bong;Auh, Q-Schick;Chun, Yang-Hyun;Lee, Jin-Yong;Hong, Jung-Pyo
    • Journal of Oral Medicine and Pain
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    • v.32 no.2
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    • pp.151-156
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    • 2007
  • Antimicrobial action of phytoncide in the mouth decrease odor-producing microorganisms. Also phytoncide has malodor effect by reaction with volatile sulfur compounds. Phytoncide has excellent malodor effect in microbiologically and chemically. This study prove the malodor effect of phytoncide by use ferrous sulfate. So I try to make new treatment method for halitosis. I get the results as follows. 1. The difference of mean value of absorbancy was 0.849 between the mean absorbancy of deposition by add phytoncide to saliva and the saliva only. 2. The difference of mean value of absorbancy was 0.701 between the mean absorbancy of deposition by add phytoncide to distilled water and the distilled water only. 3. The difference of mean value(0.849) in saliva by existence of phytoncide was larger than in double distilled water(0.701) by existence of phytoncide. Therefore, phytoncide make more deposition in saliva than double distilled water by reaction with sulfur compounds. As the results, phytoncide reaction with sulfur compounds in saliva. It take malodor action in liquid state effectively. It is thought, only the toothpaste it knows from in the limit which does not have a side effect by the human body it adds in the oral cavity of the mouth rinse and with the fact that it will be able to use positively in clinic.

Phase Changes of Soil-Cement Mixture Using Fall Cone and Heat of Hydration (Fall cone과 수화열을 이용한 흙-시멘트 혼합물의 상 변화 연구)

  • Kim Jae-Hyung;Won Jeong-Yun;Kim Sung-Pil;Chang Pyoung-Wuck
    • Journal of the Korean Geotechnical Society
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    • v.20 no.9
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    • pp.25-32
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    • 2004
  • Some amount of cements can be added into the soil with high water content to improve the engineering properties. In such a case, it is difficult to predict and figure out the phase changes of the soil-cement mixture which is closely associated with workability of the soil-cement mixture. Changes in heat of hydration and hardness of the cement pastes are known to provide the useful information about the phase changes of the soil-cement mixtures. In this study, heat of hydration and cone penetration depth were measured from the specimens of cement paste and 3 soil-cement mixtures. From the experimental results, it was found that the phase changes of the soil-cement mixtures are the same as those of cement paste, and that shear strength of the mixtures abruptly increases when the heat of hydration is minimum. Initial setting time of the mixtures coincides with the state when fall cone penetration depth was 1.0 mm and it is defined as plastic limit of the mixtures. Initial setting time of the mixtures is retarded as soil/cement ratio is increased. Measurements of heat of hydration and fall cone apparatus could be the useful tools to predict the phase changes of tile soil-cement mixtures.

Effects of Lower-Bound Resistances on Resistance Factors Calibration for Drilled Shafts (하한지지력이 현장타설말뚝의 저항계수에 미치는 영향)

  • Kim, Seok-Jung;Park, Jae-Hyun;Kim, Myoung-Mo
    • Journal of the Korean Geotechnical Society
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    • v.30 no.11
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    • pp.51-60
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    • 2014
  • Load and Resistance Factor Design (LRFD) is one of the limit state design methods, and has been used worldwide, especially in North America. Also, the study for LRFD has been actively conducted in Korea. However, the data for LRFD in Korea were not sufficient, so resistance factors suggested by AASTTO have been used for the design in Korea. But the resistance factors suggested by AASHTO represent the characteristics of bedrocks defined in the US, therefore, it is necessary to determine the resistance factors for designs in Korea, which can reflect the characteristics of bedrocks in Korea. Also, the calculated probabilities of failure from conventional reliability analyses which commonly use log-normal distribution are not realistic because of the lower tail that can be extended to zero. Therefore, it is necessary to calibrate the resistance factors considering the lower-bound resistance. Thus, this study calculates the resistance factors using thirteen sets of drilled shaft load test results, and then calibrates the resistance factors considering the lower-bound resistance corresponding to a target reliability index of 3.0. As a result, resistance factors from conventional reliability analyses were determined in the range of 0.13-0.32 for the shaft resistance, and 0.19-0.29 for the base resistance, respectively. Also, the lower bounds of resistance were determined based on the Hoek-Brown failure criteria (2002) and GSI downgrading. Considering the lower-bound resistances, resistance factors increased by 0~8% for the shaft, and 0~13% for the base, respectively.

Ultimate Strength Behavior Analysis on the Ship's Plate under Combined Load(Lateral Pressure Load and Axial Compressive Load) (조합하중을 받는 선체판부재의 최종강도거동 해석)

  • Park Jo-Shin;Ko Jae-Yong;Lee Jun-Kyo;Bae Dong-Kyun
    • Proceedings of KOSOMES biannual meeting
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    • 2005.05a
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    • pp.147-154
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    • 2005
  • The ship plating is generally subjected to combined in-plane load and lateral pressure loads. In-plane loads include axial load and edge shear, which are mainly induced by overall hull girder bending and torsion of the vessel. Lateral pressure is due to water pressure and cargo. These load components are not always applied simultaneously, but more than one can normally exist and interact Hence, for more rational and safe design of ship structures, it is of crucial importance to better understand the interaction relationship of the buckling and ultimate strength for ship plating under combined loads. Actual ship plates are subjected to relatively small water pressure except for the impact load due to slamming and panting etc. The present paper describes an accurate and fast procedure for analyzing the elastic-plastic large deflection behavior up to the ultimate limit state of ship plates under combined loads. In this paper, the ultimate strength characteristics of plates under axial compressive loads and lateral pressure loads are investigated through ANSYS elastic-plastic large deflection finite element analysis with varying lateral pressure load level.

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Comparison Study of the Impact Response Characteristics of Fixed Cylindrical Offshore Structures Considering Seawater Fluid Region (해수유체영역을 고려한 고정식 실린더형 해양구조물의 충격응답특성 비교연구)

  • Lee, Kangsu;Hong, Keyyong
    • Journal of Advanced Marine Engineering and Technology
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    • v.39 no.4
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    • pp.489-494
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    • 2015
  • This research focused on minimizing the response of fixed cylindrical offshore structures to a ship impact considering the seawater fluid part. A collision between a ship and offshore structure is generally a complex problem and it is often impractical to perform rigorous finite element analyses to include all the effects and sequences during the collision. The structural behavior of a fixed cylindrical type offshore substructure with a seawater fluid part has a simpler response and small deformation due to the dissipation of impact energy. Upon applying the impact force of a ship to the cylindrical structure, the maximum acceleration, internal energy, and plastic strain are calculated for each load cases using Ls-dyna finite element software. In the maximum cases 2.0 m/s velocity, the response result for the structure was carried out to compare between having a fluid region and no fluid region. Fluid-structure interaction analysis was performed using the ALE method, which make it possible to apply a fluid region on the impact problem. The case of a fixed cylindrical type offshore structure without a seawater fluid part can be a more conservative design.

Secondary Buckling Behavior Analysis on the Ship's Plate under Combined Load(Lateral Pressure Load and Axial Compressive Load) (조합하중을 받는 선체판부재의 2차좌굴거동 해석)

  • Park Joo-Shin;Ko Jae-Yong
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.12 no.1 s.24
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    • pp.67-74
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    • 2006
  • The ship plating is generally subjected to combined in-plane load and lateral pressure loads. In-plane loads include axial load and edge shear, which are mainly induced by overall hull girder bending and torsion rf the vessel. Lateral pressure is due to water pressure and cargo. These load components are not always applied simultaneously, but more than one can normally exist and interact. Hence, for more rational and safe design rf ship structures, it is of crucial importance to better understand the interaction relationship of the buckling and ultimate strength for ship plating under combined loads. Actual ship plates are subjected to relatively small water pressure except for the impact load due to slamming and panting etc. The present paper describes an accurate and fast procedure for analyzing the elastic-plastic large deflection behavior up to the ultimate limit state of ship plates under combined loads. In this paper, the ultimate strength characteristics of plates under axial compressive loads and lateral pressure loads are investigated secondary buckling behavior through ANSYS elastic-plastic large deflection finite element analysis with varying lateral pressure load level.

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A Study on the Navigation Control System against DPRK Vessels Within the ROK Maritime Jurisdictional Area and it's Improvement (우리나라 관할해역내 북한선박 통항통제 제도와 개선방안)

  • Lee, Jae-Kyu
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.20 no.5
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    • pp.571-578
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    • 2014
  • The boundaries of ROK maritime jurisdictional area remains unclear as two Koreas failed to draw clear maritime boundaries at the armistice agreement and there are no clear maritime boundaries with China and Japan. After the Korean War, the United Nations Command established the northern limit line(NLL) as well as the area of operations(AO) to enforce the DPRK's compliance with the armistice agreement and has been controlling all of the maritime and air activities in the region. ROK also has been controlling the passage of DPRK vessels in the area. Within the AO, third nation vessels have freedom of navigation, Yet, due to the division followed by the Korean War, ROK classifies DPRK as a hostile state and unique controling system is applied to DPRK vessels. Since the establishment of the AO, many changes have been occurring such as adoption of the UN Convention on the Law of the Sea(UNCLOS) and two Koreas' joining the UN. Also, there are continuous inter-Korean conflicts. Therefore, the geographical span of the AO needs to be reconsidered. Furthermore, a legal measure which ensures ROKN vessel's functional capability of controling DPRK vessels must be introduced. This thesis examines post-Korean War DPRK vessel control system in the Korean peninsula as well as how it should be improved.