• Title/Summary/Keyword: offset strength

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Effects of Lap Splice Details on Seismic Performance of RC Columns (RC기둥의 내진성능에 미치는 겹침 이음상세의 영향)

  • Kim, Chul-Goo;Park, Hong-Gun;Kim, Tae-Wan;Eom, Tae-Sung
    • Journal of the Earthquake Engineering Society of Korea
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    • v.20 no.6
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    • pp.351-360
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    • 2016
  • In regions of low-to-moderate seismicity, various types of lap splices are used for longitudinal reinforcement of columns at the plastic hinge zones. The seismic performance of such lap spliced columns, such as strength, deformation capacity, and energy dissipation, is affected by material strengths, longitudinal re-bar size, confinement of hoops, lap splice location, and lap splice length. In the present study, cyclic loading tests were performed for columns using three types of lap splices (bottom offset bar splice, top offset bar splice, and splice without offset bend). Lap splice length($40d_b$ and $50d_b$) was also considered as test parameters. Ties with 90-degree end hooks were provided in the lap splice length. The test results showed that strength, deformation capacity, and energy dissipation of columns significantly differed depending on the details and the length of lap splices. The bottom offset bar splice showed high ductility and energy dissipation but low strength; on the other hand, the top offset bar splice and the splice without offset bend showed high strength but moderate ductility and energy dissipation.

A Study on the Local Buckling Strength of Stainless Steel 304 (스테인리스 304 강재의 국부좌굴에 관한 연구)

  • Im, Sung Woo;Chang, In Hwa
    • Journal of Korean Society of Steel Construction
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    • v.15 no.1
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    • pp.51-57
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    • 2003
  • Current steel-framed building design codes are based on theoretical and experimental researches on the conventional structural steel. However, the yield phenomenon of austenitic stainless steel, which is characterized by continuous yielding, is quite different from that of conventional structural steel. The offset strength, which should determine the design strength, may affect the limits of width-thickness ratio of current design codes. Stub column test results showed that the limits of width-thickness ratio satisfied both ASD and LRFD codes when 0.2% offset strength was regarded as design strength. In addition, the local buckling strengths of all stainless steel stub columns did not decrease rapidly compared with those of conventional structural steel columns, even though the width-thickness ratio exceeded the design limit.

Optimum Configuration of Single Frequency Network DMB to enhance the QoS and Service coverage (QoS 개선과 서비스 커버리지 확장을 위한 단일 주파수망 지상파 DMB 최적화 배치)

  • Cho, Young-Hun;Won, Chung-Ho;Seo, Jong-Soo
    • Journal of Broadcast Engineering
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    • v.19 no.4
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    • pp.439-452
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    • 2014
  • This paper suggests the method to extend service area by using the transmit offset delay in T-DMB single frequency network (SFN). In general, synchronization of the transmit time of all site can be done by using the reference clock of GPS, which dose not reflect the details geographical characteristics and transmit specifications of each site. Applying the site-specific transmit offset delay, we could extend the service area of SFN T-DMB. Applying the transmit offset delay, it is found that the signal quality in the region of weak receive field strength was improved and upto 4~8 km service area expansion was achieved by satisfying the minimum field strength ($45dB{\mu}V/m$) recommended by the Korea Communications Commission (KCC). Site-specific offset delay was calculated considering the geographic service area characteristics, distribution of electric field strength between neighboring sites and site-specific service target area. Experiments were carried out in order to analyze impact of calculated offset delay on the T-DMB SFN and also to confirm that the offset delay extends T-DMB service coverage. The experiment was done in metropolitan T-DMB service areas.

On the Radial Velocity Offset for [OIII] Emission Line of LINER Galaxies

  • Bae, Hyun-Jin;Woo, Jong-Hak;Yagi, Masafumi;Yoon, Suk-Jin;Yoshida, Michitoshi
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.1
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    • pp.33.2-33.2
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    • 2012
  • Low-ionization nuclear emission-line region (LINER) galaxies constitute a major fraction of low-luminosity AGN population in the local Universe. In contrast to Seyfert galaxies, it is theoretically expected that LINERs would not have an outflow due to their low Eddington ratio. Using Keck/LRIS spectroscopy on a nearby LINER galaxy SDSS J091628.05+420818.7, we find a significant radial velocity offset for [OIII]${\lambda}$5007 emission line as - 50 km $s^{-1}$ blueshifted compared to systemic velocity of the galaxy, while other emission lines exhibit no or little offset. The observed [OIII] velocity offset possibly indicates an outflow of gas in the LINER galaxy, and it is probable that we only detected the [OIII] velocity offset because [OIII] ionization region is closer to the accretion disk, hence, more affected by an outflow. We further investigate the [OIII] velocity offset of -4000 SDSS AGN-host galaxies to compare the strength of AGN outflow. We find that a number of both LINER and Seyfert galaxies show [OIII] velocity offset, but the fraction of LINER galaxies with velocity offset is smaller than that of Seyfert galaxies. The preliminary results imply the presence of gas outflow in LINER galaxies, although outflow strength is probably weaker compared to Seyfert galaxies.

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Evaluation of Mechanical Properties of Three-dimensional Printed Flexible Denture Resin according to Post-polymerization Conditions: A Pilot Study

  • Lee, Sang-Yub;Lim, Jung-Hwa;Shim, June-Sung;Kim, Jong-Eun
    • Journal of Korean Dental Science
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    • v.15 no.1
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    • pp.9-18
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    • 2022
  • Purpose: The purpose of this study was to evaluate whether three-dimensional (3D)-printed flexible denture resin has suitable mechanical properties for use as a thermoplastic denture base resin material. Materials and Methods: A total of 96 specimens were prepared using the 3D printed flexible denture resin (Flexible Denture). Specimens were designed in CAD software (Tinkercad) and printed through a digital light-processing 3D printer (Asiga MAX UV). Post-polymerization process was conducted according to air exposure or glycerin immersion at 35℃ or 60℃ and for 30 or 60 minutes. The maximum flexural strength, elastic modulus, 0.2% offset yield strength, and Vickers hardness of 3D-printed flexible denture resin were assessed. Result: The maximum flexural strength ranged from 64.46±2.03 to 84.25±4.32 MPa, the 0.2% offset yield strength ranged from 35.28±1.05 to 46.13±2.33 MPa, the elastic modulus ranged from 1,764.70±64.66 to 2,179.16±140.01 MPa, and the Vickers hardness ranged from 7.01±0.40 to 11.45±0.69 kg/mm2. Conclusion: Within the limits of the present study, the maximum flexural strength, 0.2% offset yield strength, elastic modulus, and Vickers hardness are sufficient for clinical use under the post-polymerization conditions of 60℃ at 60 minutes with or without glycerin precipitation.

Experimental Study of Bending and Bearing Strength of Parallel Strand Lumber (PSL) from Japanese Larch Veneer Strand

  • OH, Seichang
    • Journal of the Korean Wood Science and Technology
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    • v.50 no.4
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    • pp.237-245
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    • 2022
  • This study examined the structural performance of experimental parallel strand lumber (PSL) from a Larch veneer strand. The prototype of PSL from a Larch veneer strand was manufactured in the experimental laboratory and tested. The bending and dowel bearing strength were determined from the modulus of elasticity (MOE), modulus of rupture (MOR), and dowel bearing strength based on a 5% offset yield load. The test results indicated that the average MOR of PSL was higher than that of 2 × 4 dimension lumber, and the average MOE of PSL was lower than that of 2 × 4 dimension lumber. A linear relationship was observed between the MOR and MOE. The allowable bending stress of PSL was derived as specified in ASTM D2915 and compared with other research. The dowel bearing strength of PSL in parallel to the grain was approximately double that perpendicular to the grain of PSL. A comparison of several theoretical calculations based on each national code for the dowel bearing strength was conducted, and some theoretical equations produced results closer to the experimental results when it was parallel to the grain, but the difference was higher in the case perpendicular to the grain. The test results showed that PSL made with Japanese larch veneer strands appeared to be suitable for a raw material of structural composite lumber (SCL) appeared to be used as a raw material for SCL.

The Optimum Offset Range on the Top of T-Bar Stiffener and Bracket (최적 T-Bar Offset(Vertical Stiffener Misalignment) 허용오차 정립)

  • Lee, Kyung-Seok;Yu, Chang-Hwa;Shon, Sang-Yong;Che, Jung-Sin
    • Special Issue of the Society of Naval Architects of Korea
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    • 2008.09a
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    • pp.1-9
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    • 2008
  • This report contains the results of structural analysis for the verification of the optimum offset range on the top of T-Bar with stiffener and BKT using at DSME Offset range as $6.0{\sim}10.0mm$ based on the 3-D FE analysis and experimental results of angie type stiffener as described in Annex 1 has been used as yard standard over ten (10) years under all Classification approval. Recently, Owner and Class have requested the confirmation for the misalignment based on the Yard's Standard so that a couple of locations for LNGC and LPGC has been investigated the structural strength by FE method using the offset ranges from 0.0 to 18.0 mm.

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Contour Parallel Offset and Tool-Path Linking Algorithm for Pocketing Using Pairwise Intersection Approach (Pairwise Intersection 방식을 이용한 윤곽 오프셋 및 공구경로 연결 알고리즘)

  • Huh, Jin-Hun;Kim, Yeoung-Il;Jun, Cha-Soo
    • Korean Journal of Computational Design and Engineering
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    • v.11 no.5
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    • pp.375-383
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    • 2006
  • Presented in this paper is a new fast and robust algorithm generating NC tool path for 2D pockets with islands. The input shapes are composed of line segments and circular arcs. The algorithm has two steps: creation of successive offset loops and linking the loops to a tool path. A modified pairwise technique is developed in order to speed up and stabilize the offset process, and the linking algorithm is focused on avoiding thin-wall cutting and minimizing tool retractions. The proposed algorithm has been implemented in C++ and some illustrative examples are presented to show the practical strength of the algorithm.

Implementation of Strength Estimation Algorithm on the Metallic Plate Fixation (금속고정용의 강도 평가 알고리즘 구현)

  • Kin, Jeong-Lae;Kim, Kyo-Ho;Lee, Ki-Young
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.9 no.3
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    • pp.45-54
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    • 2009
  • This study was developed the metallic plate for bone fixation in the neurosurgery and general surgery and plates has a finn place in bone operating and treatment. The plates can be realized to bending strength and stiffness for strength estimation. Maximum point of bending curves has a bending point(P) with maximum load which to applied nearly 0.2% offset displacement. The device's sizing has a ${\Phi}13$ and ${\Phi}18$, and algorithm of strength estimation compared a plate(${\Phi}13$, ${\Phi}18$, ${\Phi}13-{\Phi}18$). The bending strength of the curved metallic plate has to evaluate maximum of a 311N, 387N, 410N, 474N. When a displacement preserve with a load, tensile stress through to press a plate is 274N, 324N, 382N, 394N. The algorithm of strength estimation can be used to support estimation of bending strength and stiffness. Their tool bring to settlement in the new basic algorithm for evidence with varied adjustment.

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DEINKING OF COLORED OFFSET NEWSPRINT WITH ENZYME TREA TMENT IN COOPERATION WITH ULTRASONIC WAVE

  • Yimin XIE;U, Hong-W;Yanming LAI
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 1999.11b
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    • pp.149-152
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    • 1999
  • A new process for deinking of colored offset newsprint, i.e. enzyme treatment in cooperation with ultrasonic wave was developed in the present study. The physical characteristics such as fiber length, coarseness, crystallinity index of the deinked pulps were investigated and the sugar residues released from the treatment were analyzed. It was found that colored offset newsprint could be deinked effectively by cellulase treatment when ultrasonic wave was applied. The brightness increased by 5% ISO over that of control experiment and the pigment content was reduced markedly. Though the ultrasonic wave had little effect on the strength and crystallinity of the pulp, the treatment of enzyme combined with ultrasonic wave reduced the coarseness and fiber length to some extent. It was also found that ultrasonic wave could accelerate the hydrolysis of cellulose and hemicellulose during the cellulase treatment.