• 제목/요약/키워드: Standard section

검색결과 888건 처리시간 0.037초

흉강경을 이용한 1번 늑골 절제술 (Video-assisted First Rib Resection)

  • 김동진;김영태;김주현;강창현
    • Journal of Chest Surgery
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    • 제40권6호
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    • pp.463-466
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    • 2007
  • 21세 남자 환자가 우측 손의 통증, 부종 및 저린감을 주소로 내원하였다. 정맥 조영술 및 MRI scan으로 Paget-Schroetter syndrome으로 진단되었으며, 혈전 용해술을 시행하였으나 호전이 없어 흉강경하에 1번 늑골 절제술을 시행하였다. 환자는 수술 후 증상이 호전되었으며, warfarin 처방과 함께 퇴원하였다. 통상적으로 알려진 1번 늑골 절제법은 경액와 접근법(transaxillary) 혹은 쇄골상부 접근법(supra-clavivular)등이 있으나, 본 증례의 경우 흉강경하에 1번 늑골 절제술을 시행하였고 이에 결과를 보고하는 바이다.

자발적 공유 경제 방식의 개인 콘텐츠 관리 및 공유 시스템 (Private Contents Management and Sharing Service with Voluntary Sharing Economy System)

  • 류혜송;홍광진;정기철
    • 한국멀티미디어학회논문지
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    • 제19권9호
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    • pp.1698-1709
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    • 2016
  • These days, anyone can easily product and share their own content through a web service such as blogs and SNS. However, contents are being operated separately because of the space limitation in individual SNS. Therefore, it is hard to search contents efficiently in individual SNS. To solve this problem, this paper propose a "Private Contents Management and Sharing Service with Voluntary Sharing Economy System." The system is in part [Input], [Save] and it provides a way to collect the content that are scattered on the Internet based on the creation of personal index. It also proposes a more systematic content management and sharing by creating and updating the website standard index by introducing an index Coordinator concept. Furthermore in [Use] section, by providing a portion of the index as the primary search results, it avoid unclassified content list which was simply collected by users. In conclusion, unlike previous studies, this system will contribute to the acquisition and management of interspersed content and ultimately contribute to the shared activation by preventing secondary processing and unauthorized processing to the original article.

Assessment of reliability-based FRP reinforcement ratio for concrete structures with recycled coarse aggregate

  • Ju, Minkwan;Park, Kyoungsoo;Lee, Kihong;Ahn, Ki Yong;Sim, Jongsung
    • Structural Engineering and Mechanics
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    • 제69권4호
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    • pp.399-405
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    • 2019
  • The present study assessed the reliability-based reinforcement ratio of FRP reinforced concrete structure applying recycled coarse aggregate (RCA) concrete. The statistical characteristics of FRP bars and RCA concrete were investigated from the previous literatures and the mean value and standard deviation were employed for the reliability analysis. The statistics can be regarded as the material uncertainty for configuring the probability distribution model. The target bridge structure is the railway bridge with double T-beam section. The replacement ratios of RCA were 0%, 30%, 50%, and 100%. From the probability distribution analysis, the reliability-based reinforcement ratios of FRP bars were assessed with four cases according to the replacement ratio of RCA. The reinforcement ratio of FRP bars at RCA 100% showed about 17.3% higher than the RCA 0%, where the compressive strength at RCA 100% decreased up to 27.5% than RCA 0%. It was found that the decreased effect of the compressive strength of RCA concrete could be compensated with increase of the reinforcement ratio of FRP bars. This relationship obtained by the reliability analysis can be utilized as a useful information in structural design for FRP bar reinforced concrete structures applying RCA concrete.

Optimum cost design of frames using genetic algorithms

  • Chen, Chulin;Yousif, Salim Taib;Najem, Rabi' Muyad;Abavisani, Ali;Pham, Binh Thai;Wakil, Karzan;Mohamad, Edy Tonnizam;Khorami, Majid
    • Steel and Composite Structures
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    • 제30권3호
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    • pp.293-304
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    • 2019
  • The optimum cost of a reinforced concrete plane and space frames have been found by using the Genetic Algorithm (GA) method. The design procedure is subjected to many constraints controlling the designed sections (beams and columns) based on the standard specifications of the American Concrete Institute ACI Code 2011. The design variables have contained the dimensions of designed sections, reinforced steel and topology through the section. It is obtained from a predetermined database containing all the single reinforced design sections for beam and columns subjected to axial load, uniaxial or biaxial moments. The designed optimum beam sections by using GAs have been unified through MATLAB to satisfy axial, flexural, shear and torsion requirements based on the designed code. The frames' functional cost has contained the cost of concrete and reinforcement of steel in addition to the cost of the frames' formwork. The results have found that limiting the dimensions of the frame's beams with the frame's columns have increased the optimum cost of the structure by 2%, declining the re-analysis of the optimum designed structures through GA.

Amphetamine-type Stimulants in Drug Testing

  • Chung, Heesun;Choe, Sanggil
    • Mass Spectrometry Letters
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    • 제10권1호
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    • pp.1-10
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    • 2019
  • Amphetamine-type stimulants (ATS) are a group of ${\beta}$-phenethylamine derivatives that produce central nervous system stimulants effects. The representative ATS are methamphetamine and 3, 4-methylenedioxymethamphetamine (MDMA), and abuse of ATS has become a global problem. Methamphetamine is abused in North America and Asia, while amphetamine and 3, 4-methyle nedioxym ethamphetamine (Ecstasy) are abused in Europe and Australia. Methamphetamine is also the most abused drug in Korea. In addition to the conventional ATS, new psychoactive substances (NPS) including phenethylamines and synthetic cathinones, which have similar effects and chemical structure to ATS, continue to spread to the global market since 2009, and more than 739 NPS have been identified. For the analysis of ATS, two tests that have different theoretical principles have to be conducted, and screening tests by immunoassay and confirmatory tests using GC/MS or LC/MS are the global standard methods. As most ATS have a chiral center, enantiomer separation is an important point in forensic analysis, and it can be conducted using chiral derivatization reagents or chiral columns. In order to respond to the growing drug crime, it is necessary to develop a fast and efficient analytical method.

A Numerical Study on the Thermo-mechanical Response of a Composite Beam Exposed to Fire

  • Pak, Hongrak;Kang, Moon Soo;Kang, Jun Won;Kee, Seong-Hoon;Choi, Byong-Jeong
    • 국제강구조저널
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    • 제18권4호
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    • pp.1177-1190
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    • 2018
  • This study presents an analytical framework for estimating the thermo-mechanical behavior of a composite beam exposed to fire. The framework involves: a fire simulation from which the evolution of temperature on the structure surface is obtained; data transfer by an interface model, whereby the surface temperature is assigned to the finite element model of the structure for thermo-mechanical analysis; and nonlinear thermo-mechanical analysis for predicting the structural response under high temperatures. We use a plastic-damage model for calculating the response of concrete slabs, and propose a method to determine the stiffness degradation parameter of the plastic-damage model by a nonlinear regression of concrete cylinder test data. To validate simulation results, structural fire experiments have been performed on a real-scale steel-concrete composite beam using the fire load prescribed by ASTM E119 standard fire curve. The calculated evolution of deflection at the center of the beam shows good agreement with experimental results. The local test results as well as the effective plastic strain distribution and section rotation of the composite beam at elevated temperatures are also investigated.

Flow Velocity Change of David Glacier, East Antarctica, from 2016 to 2020 Observed by Sentinel-1A SAR Offset Tracking Method

  • Moon, Jihyun;Cho, Yuri;Lee, Hoonyol
    • 대한원격탐사학회지
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    • 제37권1호
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    • pp.1-11
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    • 2021
  • This study measures the change of ice flow velocity of David Glacier, one of the fast-moving glaciers in East Antarctica that drains through Drygalski Ice Tongue. In order to effectively observe the rapid flow velocity, we applied the offset tracking technique to Sentinel-1A SAR images obtained from 2016 to 2020 with 36-day temporal baseline. The resulting velocity maps were averaged and the two relatively fast points (A1 and A2) were selected for further time-series analysis. The flow velocity increased during the Antarctic summer (around December to March) over the four years' observation period probably due to the ice surface melting and reduced friction on the ice bottom. Bedmap2 showed that the fast flow velocities at A1 and A2 are associated with a sharp decrease in the ice surface and bottom elevation so that ice volumetric cross-section narrows down and the crevasses are being created on the ice surface. The local maxima in standard deviation of ice velocity, S1 and S2, showed random temporal fluctuation due to the rotational ice swirls causing error in offset tracking method. It is suggested that more robust offset tracking method is necessary to incorporate rotational motion.

Thermal stress intensity factor solutions for reactor pressure vessel nozzles

  • Jeong, Si-Hwa;Chung, Kyung-Seok;Ma, Wan-Jun;Yang, Jun-Seog;Choi, Jae-Boong;Kim, Moon Ki
    • Nuclear Engineering and Technology
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    • 제54권6호
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    • pp.2188-2197
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    • 2022
  • To ensure the safety margin of a reactor pressure vessel (RPV) under normal operating conditions, it is regulated through the pressure-temperature (P-T) limit curve. The stress intensity factor (SIF) obtained by the internal pressure and thermal load should be obtained through crack analysis of the nozzle corner crack in advance to generate the P-T limit curve for the nozzle. In the ASME code Section XI, Appendix G, the SIF via the internal pressure for the nozzle corner crack is expressed as a function of the cooling or heating rate, and the wall thickness, however, the SIF via the thermal load is presented as a polynomial format based on the stress linearization analysis results. Inevitably, the SIF can only be obtained through finite element (FE) analysis. In this paper, simple prediction equations of the SIF via the thermal load under, cool-down and heat-up conditions are presented. For the Korean standard nuclear power plant, three geometric variables were set and 72 cases of RPV models were made, and then the heat transfer analysis and thermal stress analysis were performed sequentially. Based on the FE results, simple engineering solutions predicting the value of thermal SIF under cool-down and heat-up conditions are suggested.

Enhancing fire resistance of steel bridges through composite action

  • Kodur, Venkatesh K.R.;Gil, Augusto
    • Steel and Composite Structures
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    • 제43권3호
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    • pp.353-362
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    • 2022
  • Bridge fire hazard has become a growing concern over the last decade due to the rapid increase of ground transportation of hazardous materials and resulting fire incidents. The lack of fire safety provisions in steel bridges can be a significant issue owing steel thermal properties that lead to fast degradation of steel properties at elevated temperatures. Alternatively, the development of composite action between steel girders and concrete decks can increase the fire resistance of steel bridges and meet fire safety requirements in some applications. This paper reviews the fire problem in steel bridges and the fire behavior of composite steel-concrete bridge girders. A numerical model is developed to trace the fire response of a typical bridge girder and is validated using measurements from fire tests. The selected bridge girder is composed by a hot rolled steel section strengthened with bearing stiffeners at midspan and supports. A concrete slab sitting on the top of the girder is connected to the slab through shear studs to provide full composite action. The validated numerical model was used to investigate the fire resistance of real scale bridge girders and the effect of the composite action under different scenarios (standard and hydrocarbon fires). Results showed that composite action can significantly increase the fire resistance of steel bridge girders. Besides, fire severity played an important role in the fire behavior of composite girders and both factors should be taken into consideration in the design of steel bridges for fire safety.

Comparison of Avatar Posture Formation According to 3D Virtual Garment Modeling Programs -Focusing on Cycling Movements of High-School Male Cyclist-

  • Park, Hyunjeong;Do, Wolhee
    • 한국의류학회지
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    • 제45권6호
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    • pp.965-977
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    • 2021
  • The study aimed to analyze the functional differences in 3D virtual garment programs and compare body scan data with the corresponding 3D virtual models. We selected 3D virtual garment programs, formed virtual models in a representative size for high-school male cyclists, and analyzed them using the Design-X program. The results were as follows. In the 3D virtual garment programs, the anthropometric items for virtual model forming differed significantly from the standard anthropometric items suggested by Size Korea. Comparing the lower body scan data and virtual models formed by the 3D virtual garment programs, the biggest difference was in the shapes of the waist and hips, i.e., the flatness values of the waist and hips were different for each program in the cross-section view. In the lower body, a data-input-based program was needed for changing the exact measurement position of the waist circumference and hips' shape in detail. If a 3D virtual garment program provides functions for the virtual model's joint angle input and free motion transformation, it is expected to be widely used in the sportswear industry.