• Title/Summary/Keyword: restraint

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Chloride Penetration Resistance of Concrete Mixed with High Volume Blast Furnace Slag (고르슬래그미분말을 다량 혼입한 콘크리트의 염분침투저항성)

  • Park, Ki-Cheol;Kim, Dong-Hun;Park, Shin;Lim, Nam-Gi
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2014.11a
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    • pp.40-41
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    • 2014
  • As a result of strength test on BFS concrete, those mixed with 30% and 50% of BFS8000, respectively, showed higher or equivalent strength compare to OPC. As a result of test of chloride penetration on BFS, diffusion coefficients of concrete mixed with 30% FA4000 and FA5000, respectively, showed to restrain average 6.5% of diffusion coefficient compared to OPC. And in case of BFS concrete, those mixed with BFS6000 and BFS8000, restrained diffusion of chloride ions 253% and 336%, respectively, compared to OPC. Therefore, Mixing 50% of BFS was most efficient in order to maximize restraint of chloride penetration according to metathesis of large amount. In this study, when mixing BFS to concrete for long-run durability and restraint against chloride penetration, for BFS, as fineness was higher and mixing it to concrete with less or equivalent 50% of replacement rate, there were results of higher strength compared to OPC and more efficient restraint of chloride ions.

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INJURY PERFORMANCE EVALUATION OF THE CHILD RESTRAINT SYSTEMS

  • Shin, Y.J.;Kim, H.;Kim, S.B.;Kim, H.Y.
    • International Journal of Automotive Technology
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    • v.8 no.2
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    • pp.185-191
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    • 2007
  • The new FMVSS 208, 213, 225 regulations include automatic suppression of airbags to prevent low-risk airbag deployment and the use of child seats with a rigid-bar anchor system. The regulations mean that children must sit in the rear seat, but do not include other specific safety measures for their protection. In the rear, restraint equipment consists of three-point shoulder/lap belts for the outside seats and a static two-point lap belt in the middle, with no additional devices such as pretensioners or load limiters; this is far from optimal for children. This study investigated injury rates using a 3-year-old-child dummy. ECE R44 sled tests used a booster, a speed of 48 km/h, and a 26- to 32-g rectangular deceleration pulse. While seated on a booster, the dummies were restrained by an adult shoulder/lap three-point belt. HIC_15 msec, Chest G and Nij were somewhat lower with an emergency locking retractor (ELR)+pretensioner+load limiter than with only an ELR or with ELR+pretensioner. However, the current seat-belt system results in injury rates that exceed the limit for OOP performance under the new FMVSS 208 regulations.

A Study on Evaluation of Residual Stress Redistribution for FCA Butt Weldment of Ultra-Thick YP47 Steel Plate under Tensile Cyclic Load (반복 인장 하중을 받는 YP47 극후판 Butt 용접부의 잔류응력 재분포에 관한 연구)

  • Kang, Bong Gook;Lee, Dong Ju;Shin, Sang Beom
    • Journal of Welding and Joining
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    • v.34 no.4
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    • pp.28-33
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    • 2016
  • The purpose of this study is to evaluate the redistribution of transverse residual stress in the multi-pass FCA butt weld of YP47 in the hatch coaming top plate of ultra large size containership under the tensile cyclic load. In order to do it, the configuration of modified H type specimen including restraint length was first designed to simulate the restraint condition of the butt weld in hatch coaming top plate. FE analysis procedure for evaluating the transverse residual stress was verified by comparing the calculated mean and surface residual stresses with the measured results in the test specimen. After that, the effect of the cyclic load on the redistribution of transverse residual stress was evaluated by comprehensive FEA. From the results, it was found that although the maximum transverse residual stress decreased with an increase in the applied maximum load, the effect of the cyclic load on the mean residual stress is small enough to be negligible. It is because the maximum stress of the ship corresponding to the probability of 10E-8 is less than 70% of yield stress of the weld.

A Lattice Model Study of Native Contact Restraints in Protein Folding

  • 오원석;신재민
    • Bulletin of the Korean Chemical Society
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    • v.17 no.9
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    • pp.808-813
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    • 1996
  • To explore protein folding mechanism, we simulated a folding pathway in a simplified 3×3×3 cubic lattice. In the lattice folding Monte Carlo simulations, each of the 28 possible native packing pairs that exist in the native conformation was used as a conformational restraint. The native packing restraints in the lattice model could be considered as a disulfide linkage restraint in a real protein. The results suggest that proteins denatured with a small disulfide loop can, but not always, fold faster than proteins without any disulfide linkage and than proteins with a larger disulfide loop. The results also suggest that there is a rough correlation between loop size of the native packing restraint and folding time. That is, the order of native residue-residue packing interaction in protein folding is likely dependent on the residue-residue distance in primary sequence. The strength of monomer-monomer pairwise interaction is not important in the determination of the packing order in lattice folding. From the folding simulations of five strong folding lattice sequences, it was also found that the context encoded in the primary sequence, which we do not yet clearly understand, plays more crucial role in the determination of detailed folding kinetics. Our restrained lattice model approach would provide a useful strategy to the future protein folding experiments by suggesting a protein engineering for the fast or slow folding research.

Dynamic Characteristics of Composite Thin-Walled Beams with a Chord wise Asymmetric Cross-Section: I. Single-Cell (시위 방향 비대칭 단면의 복합재료 박벽보의 동특성 연구: I. 단일-셀)

  • Kim, Keun-Taek
    • Journal of Aerospace System Engineering
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    • v.12 no.6
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    • pp.41-49
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    • 2018
  • In this study, the theoretical dynamic characteristics of a thin-walled composite beam with a single-cell of chordwise asymmetric cross-section was studied. Mathematical modeling was done by considering the transverse shear effects, the warping restraint effects, the constant taper ratio in the longitudinal direction of the beam, and the geometrical cross-section ratio. The mass coefficients, stiffness coefficients, and Eigen frequencies of the selected section were investigated. In particular, the effects of the taper ratio and cross-section ratio of the model on the Eigen frequencies were analyzed and compared when the asymmetry of the section was considered and the warping function was not corrected.

A Study on the Performance of Dynamic Restraint Manipulator for Drilling Alveolar Bone in Mandible (하악골의 치조골 골삭제를 위한 동적 제약 기구부의 성능에 관한 연구)

  • Kim, Gwang-Ho;Lee, Dong-Woon;Jeong, Sang-Hwa
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.19 no.12
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    • pp.105-112
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    • 2020
  • The increase in the edentulous jaw which occurs in the aged population has led to personal dental health concerns. In the case of dental implant surgery, the duration of a patient's recovery depends on the surgical plan and their physicical ability. A device may be required to assist a physician in controlling vibration reduction of free-hand drilling and prescribing a good treatment plan that is suitable for the patient's condition. In this work, an artificial tooth-root implant assistant manipulator was studied. The structure and the vibration analysis of the dynamic restraint manipulator that is for drilling the alveolar bone in the mandible bone were performed, and the structural stability was analyzed. Further, a virtual prototype of an artificial tooth-root implant assisted manipulator was fabricated and tested. Hence, the state of the Remote Center of Motion (RCM) point and the driving state of the manipulator were confirmed. Furthermore, the drilling experiments were performed by using materials similar to a human jawbone in order to evaluate the performance of the drilling process that is operated using the assistant manipulator.

Estimation of Sediment Discharge Controlled by Sediment-filled Check-dam in a Forested Catchment (산림유역의 만사 사방댐에 의한 토사유출 조절 효과 추정)

  • Seo, Jung Il;Chun, Kun Woo;Song, Dong Geun
    • Journal of Korean Society of Forest Science
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    • v.105 no.3
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    • pp.321-329
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    • 2016
  • To estimate the sediment discharge controlled by sediment-filled check-dam and thereby enhancing factor for check-dam design and dredging criteria, we surveyed slope failures and stream-bed fluctuation caused by geomorphic disturbances (i.e., landslides and debris flows) in Inje, Gangwondo. In general, check-dams play roles for restraining and controlling sediment discharge within a section under the design equilibrium gradient and a section under the design flood gradient, respectively. The results in this study showed same pattern: that is, the closed type check-dam, which has a design restraint sediment discharge of $2,111m^3$, estimated to control a sediment discharge of $3,996m^3$ in the stream section within 250 m right upper area immediately after the disturbances occurred in 2006. As a result, a design control sediment discharge of the check-dam was larger than its design restraint sediment discharge. This represents that the check-dam is still having an own function for controlling sediment discharge although it exceeded the designed capacity by the sediment discharged from upstream during the disturbances. Our finding suggests that the sediment discharge controlling of check-dam may need to be evaluated separately from its sediment discharge restraint. Currently, the country, however, does not consider the design control (or restraint) sediment discharges, based on the actual field survey, as criteria for check-dam design and/or dredging work. Therefore, the accumulation of the quantitative data is required to support that check-dam has functions for both restraining and controlling sediment discharge. This would be a way to develop our erosion control technology to the scientific technology equipped with a more objective and systematic aspects.

Development of a roller supported piston type loading platen reducing the frictional restraint along the interfaces between the specimen and platens under the biaxial loading condition (이축압축 조건에서 실험체/재하판 경계면상의 마찰저항 감소를 위한 롤러 지지된 피스톤 형태의 하중재하판의 개발)

  • SaGong, Myung;Kim, Se-Chyul;Lee, J.S.;Park, Du-Hee
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.10 no.3
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    • pp.303-312
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    • 2008
  • Multi-axial compression tests have been frequently adopted for the evaluation of material properties of rock cores and rock fracture model tests. Special care has to be applied on the boundary condition between the specimen and loading platen to draw the precise test results of the multi-axial compression tests. With the use of dry steel platen, the stress rotation will occur, due to the frictional restraint from the boundary between the specimen and loading platen. The restraint will deviate the expected test results under the conditions of the given external pressures. Various methods have been applied to reduce the side restraint along the specimen/loading platen interface. The steel brush type loading platen is one example of the attempts. In this paper, a new type of loading platen is introduced to overcome the limitation caused by the use of the brush type loading platen, which requires some internal space for the installation of the brushes. The new type of loading platen, roller supported steel piston type loading platen. is constituted of shot steel pistons which have sufficient stiffness to deliver the external pressure and the shaft type roller installed at the rear of the pistons. The pistons are designed to follow the local deformation of the specimens. In this paper, structural details of the loading platen are presented and frictional and biaxial compression tests results are shown to verify the required functions of the loading platen. Furthermore, calibration process is followed by a comparison between the test results and numerical analyses.

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An Experimental Study on the Effect of Anti-Histamine of the Sungmagalkuntang and Sungmagalkuntang-plus-samultang (승마갈근탕(升麻葛根湯) 및 승마갈근탕합사물탕(升麻葛根湯合四物湯)의 항(抗) Histamine 효과(效果)에 관(關)한 연구(硏究))

  • Kim, Hyun-Ah;Jeong, Ji-Cheon;Pak, Sun-Dong
    • The Journal of Dong Guk Oriental Medicine
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    • v.3
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    • pp.207-222
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    • 1994
  • In order to find out the effect of Anti-Histamine of the Sungmagalkuntang and Sungmagalkuntang-plus-samultang I've investigated the effect of the time to death, the peripheral vascular Pemeability, the amount of secretion of Gastric Juice, the total Acidity of Gastric Juice, the contraction of Intestine Tube by Histamine and the effect of the Skin-Reaction by the decrease of DNCB. These results are following ; 1. The effect of Mice's time to death by Histamine was that the injection group of sungmagalkungtang and the injection group of sungmagalkungtang-plus-samultang both have had the effect of the extention of the time to death, which indicated a statistical significance in comparison with comparative group. 2. The effect of the increased vascular permeability by Histamine was that the injection group of sungmagalkuntang and the injection group of sungmagalkuntang-plus-samultang both have had the effect of the restraint of the increased vascular permeability, which indicated a statistical significance in comparison with comparative group. 3. The effect of the the amount of the secretion of Gastric Juice by Histamine stimulus was that the injection group of sungmagalkuntang-plus-samultang only has had the effect of restraint of the increased of the secretion of Gastric Juice, which indicated a statistical significance in comparison with comparative group. 4. The effect of the change of total Acidity of Gastric Juice by Histamine's stimulus was that the injection group of sungmagalkuntang-plus-samultang only has had the effect of the restraint of the increase of total Acidity of Gastric Juice, which indicated a statistical significance in comparison with comparative group. 5. The effect of the contraction of Intestine Tube by Histamine was that sungmagalkuntang and sungmagalkuntang-plus-samultang both have had the effect of the contraction and the restraint. According to the increase of the density, the effect of the restraint was more clear. But the difference of the effects between two substances had little. 6. The effect of the reaction of skin by the decrease of DNCB was that the injection group of sungmagalkuntang and the injection group of sungmagalkuntang-plus-samultang have had the decreased effect of the Skin-Reaction in comparison with comparative group. sungmagalkuntang-plus-samultang aws more effective. In these results shown above, both sungmagalkuntang and sungmagalkuntang-plus-samultang was shown as more effective one.

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The study of optimization of restraint systems for injuries of Q6 and Q10 child dummies (Q6, Q10 어린이 인체모형 상해치에 대한 안전 구속 시스템 최적화 연구)

  • Sun, Hongyul;Lee, Seul;Kim, Kiseok;Yoon, Ilsung
    • Journal of Auto-vehicle Safety Association
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    • v.7 no.3
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    • pp.7-13
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    • 2015
  • Occupant protection performance in frontal crashes has been developed and assessed for mainly front seat occupants over many years, and in recent years protection of rear seat occupants has also been extensively discussed. Unlike the front seats, the rear seats are often occupied by children seated in rear-facing or forward - facing child restraint systems, or booster seats. In the ENCAP, child occupant protection assessments using 18-month-old(P1.5) and 3-year-old(P3) test dummies in the rear seat have already been changed to new type of 18-month-old (Q1.5)and 3-year-old(Q3) test dummies. In addition, ENCAP are scheduled with the development and introduction of test dummies of 6-year-old (Q6) and 10.5-year-old children(Q10) starting 2016. In KNCAP, Q6 and Q10 child dummies will be introduced in 2017 as well. Automobile manufacturers need to develop safety performance for new child dummies closely. In this paper, we focused on Q6 and Q10 child dummies sitting in child restraint system. Offset frontal crash tests were conducted using two types of test dummies, Q6 and Q10 child dummies, positioned in the rear seat. Q6 and Q10 were used to compare dummy kinematics in rear seating positions between Q6 behind the driver's seat and Q10 behind the front passenger's seat. The full vehicle sled test results of both dummies were conducted with different restraint systems. It showed that several injury and image data was collected as the result of the full vehicle sled test. Based on the results of these investigations, this paper describes which factor is most important and combination is the best performance when evaluating rear seat occupant protection for Q6 and Q10 child dummies.