• Title/Summary/Keyword: Strong Spring

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Vertical seismic response analysis of straight girder bridges considering effects of support structures

  • Wang, Tong;Li, Hongjing;Ge, Yaojun
    • Earthquakes and Structures
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    • v.8 no.6
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    • pp.1481-1497
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    • 2015
  • Vertical earthquake ground motion may magnify vertical dynamic responses of structures, and thus cause serious damage to bridges. As main support structures, piers and bearings play an important role in vertical seismic response analysis of girder bridges. In this study, the pier and bearing are simplified as a vertical series spring system without mass. Then, based on the assumption of small displacement, the equation of motion governing the simply-supported straight girder bridge under vertical ground motion is established including effects of vertical deformation of support structures. Considering boundary conditions, the differential quadrature method (DQM) is applied to discretize the above equation of motion into a MDOF (multi-degree-of-freedom) system. Then seismic responses of this MDOF system are calculated by a step-by-step integration method. Effects of support structures on vertical dynamic responses of girder bridges are studied under different vertical strong earthquake motions. Results indicate that support structures may remarkably increase or decrease vertical seismic responses of girder bridges. So it is of great importance to consider effects of support structures in structural seismic design of girder bridges in near-fault region. Finally, optimization of support structures to resist vertical strong earthquake motions is discussed.

Screening for Antitumor Efficacy from the Wild Plants in Korea (한국산 천연항종양성 자원의 Screening에 대하여)

  • 이상래
    • Korean Journal of Plant Resources
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    • v.5 no.2
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    • pp.85-93
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    • 1992
  • This experiment was Conducted ta screening for the anti-cancer efficacy from the wild plants which are naturally growing in the Korea. The results are as follows. The results were shown thatZea may L. nad significantly effects on mediculal efficacy anganist anti-tumor by usulg the totalpacked cell volume methods and also, severals plants, such as Sofonum nigrum, Patrinia hispidoBunge, Eragrostis, ferrugenia Beauv, Salaginela pouzolgiana Spring, Platrycarya strobilacea Bunge,Codonopsis lanceolata Benth. et Hook fil. which are collected from Giri and Mooju mountain in Koreaand Nagano in Japan were showed effects on auti-tumor. But the pharmaceologial activities ofPharbitis nil Choisy was believed to strong effec on anti - cancer tumors, while toxicity of its wasshown high that induced te kill all used mice. Extraction of Patrinia hispida Bunge, Pharbitis nilChoisy, Toilis japonica DC, Eragrostis erruginea Beauv. and Forsythia koreana Nakai showed effec-tively supressed on growth rate of cancer tumor by the below 50 percent of T/C ratio at 30mg /mlof extraction from plant. That Is strong activity while Reynouxria japonica Houtt. was observed onlymild activities. The above results many possibly suggest that Patrinia hispido Bunge and Eragrostisferrugina Beauv. inhibited the growth of cancer tumor by the both total packed cell volume methodand cytotoxicity method. Although basic research is still going on, we will find out an accurate moth-od for developing useful medicinal plant to improve pharmacological activites against anti-cancertumor, especialy, in Eragrostis ferruginea Beauv.

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Fast and Accurate Single Image Super-Resolution via Enhanced U-Net

  • Chang, Le;Zhang, Fan;Li, Biao
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.15 no.4
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    • pp.1246-1262
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    • 2021
  • Recent studies have demonstrated the strong ability of deep convolutional neural networks (CNNs) to significantly boost the performance in single image super-resolution (SISR). The key concern is how to efficiently recover and utilize diverse information frequencies across multiple network layers, which is crucial to satisfying super-resolution image reconstructions. Hence, previous work made great efforts to potently incorporate hierarchical frequencies through various sophisticated architectures. Nevertheless, economical SISR also requires a capable structure design to balance between restoration accuracy and computational complexity, which is still a challenge for existing techniques. In this paper, we tackle this problem by proposing a competent architecture called Enhanced U-Net Network (EUN), which can yield ready-to-use features in miscellaneous frequencies and combine them comprehensively. In particular, the proposed building block for EUN is enhanced from U-Net, which can extract abundant information via multiple skip concatenations. The network configuration allows the pipeline to propagate information from lower layers to higher ones. Meanwhile, the block itself is committed to growing quite deep in layers, which empowers different types of information to spring from a single block. Furthermore, due to its strong advantage in distilling effective information, promising results are guaranteed with comparatively fewer filters. Comprehensive experiments manifest our model can achieve favorable performance over that of state-of-the-art methods, especially in terms of computational efficiency.

Being True to Oneself: Sewol Ferry Disaster and Homeland Politics of Korean Immigrants in Britain

  • Shin, Mijoo;Han, Heejin
    • Analyses & Alternatives
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    • v.3 no.2
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    • pp.33-57
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    • 2019
  • After the tragic incident of the sinking of Sewol in spring 2014, Korean migrants in Britain began to hold street protests in London. These protestors condemned the Korean government for the lack of appropriate responses to the accident, and for its failure to conduct proper investigation on the issue. The small group of protestors held silent street protests every month at Trafalgar Square, despite not gaining much media coverage nor public attention. These migrants' almost three-year long protest outside their homeland is puzzling. Not only did they live in Britain for a long time to the extent that they regard the country as their second home, but they also exert scant amount of influence on the political landscape in South Korea. What can then account for these individuals' participation in activism related to their homeland politics? In this paper, we utilize the concept of 'moral identity' to explain the behaviors of Korean migrants involved in the street protests. These migrants had strong 'moral identity', which triggered a sense of responsibility to act when their cherished moral values were jeopardized. Korean migrants who possessed a strong sense of moral identity placed huge importance on living in accordance with their moral values. It is a way of upholding their self-esteem and sustaining their ideal self.

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Basic Marine Environmental Characteristics of Suspended Sediments in the Inner Shelf Zone off Tae-An Peninsula, West Coast of Korea (한반도 서해 태안반도 연근해 부유퇴적물의 기초 해양환경적 특성)

  • 최진용;박용안
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.1 no.1
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    • pp.46-54
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    • 1996
  • A study on the concentrations of total suspended matters (TSM) and their distribution pattern was conducted off the west coast of Tae-An Peninsula during the spring season. Especially non-destructive and fine-tuned analysis for the size-distribution of suspended matters was made using SPECTREX instrument. Water masses were characterized by the typical tidal front, with vertically homogenous coastal waters and the strong thermoclines on the offshore area. Concentrations of suspended matters were generally less than 10 mg/l, but the concentrations increased up to 25 mg/l at the bottom waters and mid-depth waters. Mean particle size of the suspended matters were generally 5-6$\mu\textrm{m}$ and 8-10$\mu\textrm{m}$ for the fine-grained suspended matters and the coarse-grained suspended matters, respectively. They are considered to be composed dominantly of detrital materials. On the coastal area, landward side of tidal front, bottom sediments can be easily resuspended by the strong tidal currents, and therefore, deposition of suspended materials are thought to be rather limited. On the offshore area, however, suspended sediments mostly supplied from the northern part of the present study area near Kyunggi Bay are thought to be transported southward and/or southwestward along the mid- depth layer of strong thermocline.

Synoptic Structures and Precipitation Impact of Extratropical Cyclones Influencing on East Asia Megacities: Seoul, Beijing, Tokyo (동아시아 대도시에 영향을 미치는 온대저기압의 특성 및 강수 영향 비교: 서울, 베이징, 도쿄)

  • Kim, Donghyun;Lee, Jaeyeon;Kang, Joonsuk M.;Son, Seok-Woo
    • Atmosphere
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    • v.31 no.1
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    • pp.45-60
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    • 2021
  • The synoptic structures and precipitation impact of extratropical cyclones (ETCs) influencing on the three adjacent megacities in East Asia, i.e., Beijing (Beijing ETCs), Seoul (Seoul ETCs) and Tokyo (Tokyo ETCs), are analyzed using ERA-interim reanalysis data from 1979 to 2018. Individual ETC tracks are identified with the automated tracking algorithm applied to 850-hPa relative vorticity field. Among four seasons, ETCs are the most frequent in spring. In this season, Beijing ETCs are mainly generated at the leeside of Altai-Sayan Mountains and primarily develop through interaction between the upper-level trough and lower-level cyclonic circulation. For Seoul ETCs, the leesides of Altai-Sayan Mountains (Seoul-N ETCs) and Tibetan Plateau (Seoul-S ETCs) are main genesis regions and the features of ETCs are different according to the genesis regions. While Seoul-N ETCs mainly develope by the same mechanism of Beijing ETCs, strong diabatic heating due to vapor transport is responsible for the genesis of Seoul-S ETCs. Tokyo ETCs are originated from the leesides of Tibetan Plateau and Kuroshio-Oyashio Extension regions, and strong diabatic heating as well as interaction between upper and lower levels determines the genesis of these ETCs. The precipitation impact resulting from ETCs become strong in the order of Beijing ETCs, Seoul-N ETCs, Seoul-S ETCs, and Tokyo ETCs and accounts for up to 40%, 27%, 52%, and 70% of regional precipitation, respectively.

Physical Environments of Suyong Bay during the Rip Current Events at Haeundae - August 2009 (해운대 이안류 발생 시 수영만의 물리환경 - 2009년 8월)

  • Lee, J.C.;Kim, D.H.
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.15 no.3
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    • pp.110-114
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    • 2010
  • A data set of current, wind and wave height measured at the monitoring buoy and sea level at Busan harbor were analyzed to explain the physical conditions during the strong rip current events at Haeundae Beach of Suyeong Bay during 13~15 August 2009. Tidal current, with spring-neap variations, has similar average speed to the short-term non-tidal currents. The common features at the time of rip currents are the strong northeasterly wind and superposition of tidal and non-tidal currents both flowing toward the coast. However on 14 August when the rip current did not occur, tide and wave height were similar to the rip-current cases but the tidal and non-tidal current were to nearly opposite directions. While strong winds produce large waves thus the basic condition for rip current but its influence on the local circulation in the bay is relatively small. Of the three adjacent beaches, only at Haeundae the rip currents are reported. This difference may be due to the unique bottom topography featured by underwater hill in the central region off Haeundae which can decay the incoming waves, tides and currents to intensify the rip current.

Screening the Antioxidant Components and Antioxidant Activitiy of Extracts Derived from Five Varieties of Edible Spring Flowers (식용 봄꽃(개나리꽃, 진달래꽃, 목련꽃, 벚꽃) 추출물의 항산화성분과 항산화활성 검색)

  • Kim, Su-Min;Kim, Do-Yeon;Park, Hye-Ri;Seo, Ji-Hye;Yeom, Bo-Min;Jin, Yoo-Jung;Pyo, Young-Hee
    • Korean Journal of Food Science and Technology
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    • v.46 no.1
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    • pp.13-18
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    • 2014
  • This study was designed to investigate the in vitro antioxidant potentials and the antioxidant components of 80% ethanolic extracts prepared from five edible spring flowers. The contents of total phenols (14.1-18.9 mg gallic acid equivalents/g of dry weight; DW), flavonoids (0.3-4.9 mg catechin equivalents), total carotenoids ($1.9-578.1{\mu}g$ ${\beta}$-carotene equivalents), and proanthocyanidins (2.8-23.5 mg catechin equivalents), were determined by spectrophotometry. In addition, the content of ascorbic acid (0.71-1.31 mg) was determined using HPLC with UV detection. All varieties of the flower examined showed antioxidant potential (1.2-46.1 mM Trolox equivalents/g DW), which was measured by the radical scavenging activity and the reducing power. Of the five flowers analyzed, Prunus avium L. showed the highest antioxidant activity. A strong correlation was found between the ascorbic acid ($r^2=0.75$), flavonoids ($r^2=0.71$), and total phenolic content ($r^2=0.64$) and the antioxidant parameters, suggesting that these components are likely significant contributors to the antioxidant capacity of the five spring flowers.

A Comparative Study between Korean and Japanese System concerning Long-Life Housing (한.일 장수명 공동주택관련 제도 비교 연구)

  • Lee, Bo-Ra;Hwang, Eun-Kyoung;Kim, Soo-Am
    • Proceeding of Spring/Autumn Annual Conference of KHA
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    • 2006.11a
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    • pp.448-451
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    • 2006
  • Multi-residential housing in Korea has many problems basically because maintenance, management, and remodelling have been done without considering building elapse and residents' needs. Residential open building has been suggested as one of the solutions. Even though the techniques have been actively developed for residential open building in Japan and the Netherlands, some obstacles are still existing. Especially in Korea, due to the lack of studies for facilitating residential open building, the development and popularization of residential open building are delayed. With the concern that the facilitation of process and systems is as important as technical development, the evaluation of process and systems is needed for promoting residential open building. As result, strong investigation of current situation can offer basic foundation to facilitate residential open building. The purpose of this study is to propose plans to facilitate residential open building in Korea through a comparative study between Korean and Japanese system.

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A Study on Optimal Design Factors of Frictional bearing for Isolated Bridges (교량의 마찰형 지진격리장치 최적 인자 결정에 관한 연구)

  • 고현무;박관순;김동석;송현섭
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2002.03a
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    • pp.451-458
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    • 2002
  • To secure structures from strong earthquakes occurred recently and design economically seismic isolation design is spread rapidly. Specially, frictional isolator has superiority in application to bridge because it has many advantages. however, because isolator lies between pier and girder, responses of pier and superstructure contradict each other and we need to control the two responses to minimize the bridge's failure probability. In this study, frictional coefficient and horizontal stiffness is defined as design parameters of frictional isolator. the optimal design parameters of frictional isolator to minimize the bridge's failure probability are presented according to strength of earthquake and soil conditions. The result says that optimal friction coefficient is higher as the strength of earthquake is increased. And it is also higher as the soils are more flexible. But, optimal horizontal stiffness of rubber spring is insensitive to strength of earthquake and soil condition.

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