• 제목/요약/키워드: IAB

검색결과 26건 처리시간 0.02초

Study on UxNB Network Deployment Method toward Mobile IAB

  • Keewon Kim;Jonghyun Kim;Kyungmin Park;Tae-Keun Park
    • 한국컴퓨터정보학회논문지
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    • 제28권12호
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    • pp.105-114
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    • 2023
  • 본 논문은 모바일 IAB를 향한 UxNB 네트워크 배포 및 운영 방안을 제안한다. SDN(Software Defined Network) 기반으로 UxNB 네트워크를 운영하여, 이동 통신 서비스를 원하는 지역에 UxNB를 배포한다. 서비스 지역에 UxNB를 배포한 후, IAB를 설정하여 이동 통신 서비스를 수행할 수 있다. 이를 위해 본 논문에서는 먼저 UAV 컨트롤러(UAV controller)와 SDN 컨트롤러(SDN controller)로 구성되는 UxNB 네트워크 컨트롤러(UxNB NC; UxNB network controller)를 제안하고 필요한 기능들을 기술한다. 다음으로 UxNB 네트워크를 배포하고 운영할 수 있는 시나리오를 단계별로 상세하게 제시한다. 또한 UxNB 네트워크 컨트롤러의 위치, UxNB에 대한 UAV 컨트롤러 제어 명령 전달 방법, UxNB 네트워크를 위한 IAB 적용 방법, UxNB 네트워크의 최적화, UxNB 네트워크의 RLF(radio link failure) 복구 및 UxNB 네트워크의 보안(security)에 대한 향후 연구를 논한다. 제안한 UxNB NC 아키텍처와 UxNB 네트워크 배포 및 운영 방안을 이용하여 모바일 IAB에 UxNB 네트워크를 원활하게 통합할 수 있을 것으로 기대한다.

International Education, Qualification and Certification Systems in Welding

  • L., Quintino;R., Ferraz;I., Fernandes
    • Journal of Welding and Joining
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    • 제25권6호
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    • pp.84-95
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    • 2007
  • The International System for Education and Qualification of Welding Personnel has been implemented based on the harmonized European System for education and qualification of welding personnel. This paper gives an overview of the International System focusing on the training guidelines and the quality assurance system developed. Systems for harmonization of Certification of Welding Personnel and for supporting companies using welding to implement ISO 3834 have been developed by EWF and are presently being transferred to IIW in line with the EWF/IIW agreement established in 2000.

Response of integral abutment bridges under a sequence of thermal loading and seismic shaking

  • Tsinidis, Grigorios;Papantou, Maria;Mitoulis, Stergios
    • Earthquakes and Structures
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    • 제16권1호
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    • pp.11-28
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    • 2019
  • This article investigates the response of Integral Abutment Bridges (IAB) when subjected to a sequence of seasonal thermal loading of the deck followed by ground seismic shaking in the longitudinal direction. Particular emphasis is placed on the effect of pre-seismic thermal Soil-Structure Interaction (SSI) on the seismic performance of the IAB, as well as on the ability of various backfills configurations, to minimize the unfavorable SSI effects. A series of two-dimensional numerical analyses were performed for this purpose, on a complete backfill-integral bridge-foundation soil system, subjected to seasonal cyclic thermal loading of the deck, followed by ground seismic shaking, employing ABAQUS. Various backfill configurations were investigated, including conventional dense cohesionless backfills, mechanically stabilized backfills and backfills isolated by means of compressive inclusions. The responses of the investigated configurations, in terms of backfill deformations and earth pressures, and bridge resultants and displacements, were compared with each other, as well as with relevant predictions from analyses, where the pre-seismic thermal SSI effects were neglected. The effects of pre-seismic thermal SSI on the seismic response of the coupled IAB-soil system were more evident in cases of conventional backfills, while they were almost negligible in case of IAB with mechanically stabilized backfills and isolated abutments. Along these lines, reasonable assumptions should be made in the seismic analysis of IAB with conventional sand backfills, to account for pre-seismic thermal SSI effects. On the contrary, the analysis of the SSI effects, caused by thermal and seismic loading, can be disaggregated in cases of IAB with isolated backfills.

Integral Abutment Bridge behavior under uncertain thermal and time-dependent load

  • Kim, WooSeok;Laman, Jeffrey A.
    • Structural Engineering and Mechanics
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    • 제46권1호
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    • pp.53-73
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    • 2013
  • Prediction of prestressed concrete girder integral abutment bridge (IAB) load effect requires understanding of the inherent uncertainties as it relates to thermal loading, time-dependent effects, bridge material properties and soil properties. In addition, complex inelastic and hysteretic behavior must be considered over an extended, 75-year bridge life. The present study establishes IAB displacement and internal force statistics based on available material property and soil property statistical models and Monte Carlo simulations. Numerical models within the simulation were developed to evaluate the 75-year bridge displacements and internal forces based on 2D numerical models that were calibrated against four field monitored IABs. The considered input uncertainties include both resistance and load variables. Material variables are: (1) concrete elastic modulus; (2) backfill stiffness; and (3) lateral pile soil stiffness. Thermal, time dependent, and soil loading variables are: (1) superstructure temperature fluctuation; (2) superstructure concrete thermal expansion coefficient; (3) superstructure temperature gradient; (4) concrete creep and shrinkage; (5) bridge construction timeline; and (6) backfill pressure on backwall and abutment. IAB displacement and internal force statistics were established for: (1) bridge axial force; (2) bridge bending moment; (3) pile lateral force; (4) pile moment; (5) pile head/abutment displacement; (6) compressive stress at the top fiber at the mid-span of the exterior span; and (7) tensile stress at the bottom fiber at the mid-span of the exterior span. These established IAB displacement and internal force statistics provide a basis for future reliability-based design criteria development.

Behavior of integral abutment bridge with partially protruded piles

  • Park, Min-Cheol;Nam, Moon S.
    • Geomechanics and Engineering
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    • 제14권6호
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    • pp.601-614
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    • 2018
  • This study presents structural and parametric analyses on the behavior of an integrated and pile-bent abutment with mechanically stabilized earth wall (IPM) bridge. The IPM bridge is an integral abutment bridge (IAB) with partially protruded piles, which excludes earth pressure by means of a mechanically stabilized earth wall developed by the authors. The results of the analysis indicate that the IPM bridge, as any other IAB, is influenced to a large extent by temperature and time-dependent loads. When these loads are applied, the stress on a pile in the IPM bridge decreases as the displacement of the pile top increases, because the piles protrude from the ground surface and no soil reaction is generated on the protruded pile. Because the length of an IAB is restricted by the forces acting on its piles, the IPM bridge is an effective alternative to extend its length.

단부격벽 일체형 PSC거더를 갖는 반일체식 교량의 시공성 연구 (Study on the Field Construction of Semi-Integral Bridge with PSC Girder Integrating End-Diaphragm)

  • 박종면;김진배;전성용;김충식;유성근;박중배;임정훈
    • 복합신소재구조학회 논문집
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    • 제5권2호
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    • pp.21-26
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    • 2014
  • This paper introduces general concepts of jointless bridges and field construction case of semi-integral bridge with psc girder integrating end-diaphragm. The expansion joints need to satisfy thermal and safety conditions of bridges. General bridges with joints have some problems, which are frequently replacement cycle time from mechanical damage or unstable movement, maintenance cost and more. To solve these problems, Integral Abutment Bridges(IAB) have been applied overseas in the 1930s. In Korea, first IAB was constructed in the early 2000s and precast IAB systems was invented and applied lately. Kyungshin overpass bridge in Incheon is the Semi-IAB constructed, the span length is 2@35=70m and the width is 13.9m. The original plan was to use general joint bridge but design field changed with expectations for advanced economic estimation and maintenance. This changed method of B.I.B bridge construction provided not only workability, construction cost but also safety improvement at the same time.

Reliability-based design of prestressed concrete girders in integral Abutment Bridges for thermal effects

  • Kim, WooSeok;Laman, Jeffrey A.;Park, Jong Yil
    • Structural Engineering and Mechanics
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    • 제50권3호
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    • pp.305-322
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    • 2014
  • Reliability-based design limit states and associated partial load factors provide a consistent level of design safety across bridge types and members. However, limit states in the current AASHTO LRFD have not been developed explicitly for the situation encountered by integral abutment bridges (IABs) that have unique boundary conditions and loads with inherent uncertainties. Therefore, new reliability-based limit states for IABs considering the variability of the abutment support conditions and thermal loading must be developed to achieve IAB designs that achieve the same safety level as other bridge designs. Prestressed concrete girder bridges are considered in this study and are subjected to concrete time-dependent effects (creep and shrinkage), backfill pressure, temperature fluctuation and temperature gradient. Based on the previously established database for bridge loads and resistances, reliability analyses are performed. The IAB limit states proposed herein are intended to supplement current AASHTO LRFD limit states as specified in AASHTO LRFD Table 3.4.1-1.

Recombinant Interferon-${\alpha}$ Cross-linked with Thymosin ${\alpha}$1 is Biologically Active

  • Jeong, Jee-Yeong;Chung, Hye-Shin
    • BMB Reports
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    • 제29권4호
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    • pp.365-371
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    • 1996
  • Partially reduced interferon-a ($IFN-{\alpha}$) was cross-linked with thymosin ${\alpha}1$ ($T{\alpha}1$) using sulfo-succinimidyl (4-iodoacetyl) amino benzoate (SIAB), a bifunctional cross-linking reagent. The partially reduced $IFN-{\alpha}$ optimal for the cross-linking reaction was obtained by incubating native $IFN-{\alpha}$ with 0.5 mM DTT at $30^{\circ}C$ for 60~100 min. $T{\alpha}1$ was activated by incubating with sulfo-SIAB at $37^{\circ}C$ for 30 min to produce $T{\alpha}1-IAB$. The $T{\alpha}1-IFN-{\alpha}$ cross-linking was achieved by the reaction of the partially reduced $IFN-{\alpha}$ with $T{\alpha}1-IAB$. This cross-linking was between the sulfhydryl group of Cys1 in $IFN-{\alpha}$ and the N-terminal amino group of $T{\alpha}1$ through acetyl amino benzoate as a spacer. The immunological activity of the cross-linked molecule showed the same extent as that of $T{\alpha}1$, and most of the antiviral activity was retained compared to that of the partially reduced $IFN-{\alpha}$.

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Fragility evaluation of integral abutment bridge including soil structure interaction effects

  • Sunil, J.C.;Atop, Lego;Anjan, Dutta
    • Earthquakes and Structures
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    • 제20권2호
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    • pp.201-213
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    • 2021
  • Contrast to the conventional jointed bridge design, integral abutment bridges (IABs) offer some marked advantages like reduced maintenance and enhanced service life of the structure due to elimination of joints in the deck and monolithic construction practices. However, the force transfer mechanism during seismic and thermal movements is a topic of interest owing to rigid connection between superstructure and substructure (piers and abutments). This study attempts to model an existing IAB by including the abutment backfill interaction and soil-foundation interaction effects using Winkler foundation assumption to determine its seismic response. Keeping in view the significance of abutment behavior in an IAB, the probability of damage to the abutment is evaluated using fragility function. Incremental Dynamic Analysis (IDA) approach is used in this regard, wherein, nonlinear time history analyses are conducted on the numerical model using a selected suite of ground motions with increasing intensities until damage to abutment. It is concluded from the fragility analysis results that for a MCE level earthquake in the location of integral bridge, the probability of complete damage to the abutment is minimal.

Analysis of the Relationship between MHC-DRB1 Gene Polymorphism and Hydatidosis in Kazakh Sheep

  • Li, Ren-Yan;Jia, Bin;Zhang, Wen-Ju;Zhao, Zong-Sheng;Shi, Guo-Qing;Shen, Hong;Peng, Qiang;Lv, Li-Min;Zhou, Qi-Wei;Du, Ying-Chun
    • Asian-Australasian Journal of Animal Sciences
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    • 제23권9호
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    • pp.1145-1151
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    • 2010
  • The objective of this work was to analyze the relationship between ovine major histocompatibility complex (MHC) DRB1 gene polymorphism and genetic resistance to hydatidosis in Kazakh sheep. The Ovar (ovine MHC) class II DRB1 second exon was amplified by polymerase chain reaction (PCR) from DNA samples of 702 Kazakh sheep, including 302 sheep with hydatidosis and 400 health controls. PCR products were characterized by the restriction fragment length polymorphism (RFLP) technique using five restriction enzymes, i.e., MvaI, HaeIII, SacI, SacII and Hin1I, yielding 14 alleles and 28 genotypes. Comparing the frequency of genotypes in hydatidosis sheep with the control group, it was found that the genotype frequencies of MvaIbc, Hin1Iab, SacIIab, HaeIIIde, HaeIIIdf and HaeIIIdd in control sheep were significantly (p<0.01) higher than in hydatidosis sheep, indicating that a significant correlation existed between these genotypes and resistance to hydatidosis. Genotype frequencies of MvaIbb, SacIIaa, Hin1Ibb and HaeIIIef in sheep with hydatidosis were extremely significantly (p<0.01) higher than in the control group, and the genotype frequency of HaeIIIab was significantly higher (p<0.05), indicating that a marked correlation existed between these genotypes and susceptibility to hydatidosis. By way of analyzing haplotype with these resistant genotypes, the hydatidosis resistant haplotype MvaIbc-SacIIab-Hin1Iab of Kazakh sheep was screened out, and then verified through artificial hydatid infection in sheep. The results indicated that the infection rate of sheep with the resistant haplotype of hydatidosis was significantly lower (p<0.01) than without this resistant haplotype. It showed that the genic haplotype MvaIbc-SacIIab-Hin1Iab of Ovar-DRB1 exon 2 was the resistant haplotype of hydatidosis in Kazakh sheep.