• Title/Summary/Keyword: restraints

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Influence of Elastic Restraints and Tip Mass at Free End on stability of Leipholz Column (Leipholz 기둥의 안정성에 미치는 자유단의 탄성구속과 말단질량의 영향)

  • 윤한익;박일주;진종태;김영수
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1996.04a
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    • pp.309-315
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    • 1996
  • An analysis is presented on the stability of elastic cantilever column subjected to uniformly distributed follower forces as to the influence of the elastic restraints and a tip mass at the free end. The elastic restraints are formed by both the translational and the rotatory springs. For this purpose, the governing equations and boundary conditions are derived by using Hamilton's principle, and the critical flutter loads and frequencies are obtained from the numerical evaluation of the eigenvalue functions of this elastic system. The added tip mass increases as a whole the critical flutter load in this system, but the presence of its moment of inertia of mass has a destabilizing effect. The existence of the translational and rotatory spring at the free end increases the critical flutter load of the elastic cantilever column. Nevertheless their effects on the critical flutter load are not uniform because of their coupling. The translational spring restraining the end of cantilever column decreases the critical flutter load by coupling with a large value of tip mass, while by coupling with the moment of inertia of tip mass its effect on the critical flutter load is contrary. The rotatory spring restraining the free end of cantilever column increases the critical flutter load by coupling with the tip mass, but decreases it by coupling with the moment of inertia of tip mass.

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Strategy for Determining the Structures of Large Biomolecules using the Torsion Angle Dynamics of CYANA

  • Jee, Jun-Goo
    • Journal of the Korean Magnetic Resonance Society
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    • v.20 no.4
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    • pp.102-108
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    • 2016
  • With the rapid increase of data on protein-protein interactions, the need for delineating the 3D structures of huge protein complexes has increased. The protocols for determining nuclear magnetic resonance (NMR) structure can be applied to modeling complex structures coupled with sparse experimental restraints. In this report, I suggest the use of multiple rigid bodies for improving the efficiency of NMR-assisted structure modeling of huge complexes using CYANA. By preparing a region of known structure as a new type of residue that has no torsion angle, one can facilitate the search of the conformational spaces. This method has a distinct advantage over the rigidification of a region with synthetic distance restraints, particularly for the calculation of huge molecules. I have demonstrated the idea with calculations of decaubiquitins that are linked via Lys6, Lys11, Lys27, Lys29, Lys33, Lys48, or Lys63, or head to tail. Here, the ubiquitin region consisting of residues 1-70 was treated as a rigid body with a new residue. The efficiency of the calculation was further demonstrated in Lys48-linked decaubiquitin with ambiguous distance restraints. The approach can be readily extended to either protein-protein complexes or large proteins consisting of several domains.

Risk Factors for Deliberate Self-extubation (기관 내 삽관환자의 의도적 자가발관 위험요인)

  • Cho, Young Shin;Yeo, Jung Hee
    • Journal of Korean Academy of Nursing
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    • v.44 no.5
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    • pp.573-580
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    • 2014
  • Purpose: This study was conducted to analyze intubation survival rates according to characteristics and to identify the risk factors affecting deliberate self-extubation. Methods: Data were collected from patients' electronic medical reports from one hospital in B city. Participants were 450 patients with endotracheal intubation being treated in intensive care units. The collected data were analyzed using Kaplan-Meier estimation, Log rank test, and Cox's proportional hazards model. Results: Over 15 months thirty-two (7.1%) of the 450 intubation patients intentionally extubated themselves. The patients who had experienced high level of consciousness, agitation. use of sedative, application of restraints, and day and night shift had significantly lower intubation survival rates. Risk factors for deliberate self-extubation were age (60 years and over), unit (neurological intensive care), level of consciousness (higher), agitation, application of restraints, shift (night), and nurse-to-patient ratio (one nurse caring for two or more patients). Conclusion: Appropriate use of sedative drugs, effective treatment to reduce agitation, sufficient nurse-to-patient ratio, and no restraints for patients should be the focus to diminish the number of deliberate self-extubations.

Enhancement of the buckling strength of glass beams by means of lateral restraints

  • Belis, J.;Impe, R. Van;Lagae, G.;Vanlaere, W.
    • Structural Engineering and Mechanics
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    • v.15 no.5
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    • pp.495-511
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    • 2003
  • New material applications and transparency are desired by contemporary architects. Its superb transparency and high strength make glass a very suitable building material -in spite of its brittleness- even for primary load bearing structures. Currently we will focus on load bearing glass beams, subjected to different loading types. Since glass beams have a very slender, rectangular cross section, they are sensitive to lateral torsional buckling. Glass beams fail under a critical buckling load at stresses that lie far below the theoretical simple bending strength, due to the complex combination of torsion and out-of-plane bending, which characterises the instability phenomenon. The critical load can be increased considerably by preventing the upper rim from moving out of the beam's plane. Different boundary conditions are examined for different loading types. The load carrying capacity of glass beams can be increased three times and more using relatively simple, cheap lateral restraints.

Comparison of NMR structures refined under implicit and explicit solvents

  • Jee, Jun-Goo
    • Journal of the Korean Magnetic Resonance Society
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    • v.19 no.1
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    • pp.1-10
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    • 2015
  • Refinements with atomistic molecular dynamics (MD) simulation have contributed to improving the qualities of NMR structures. In most cases, the calculations with atomistic MD simulation for NMR structures employ generalized-Born implicit solvent model (GBIS) to take into accounts solvation effects. Developments in algorithms and computational capacities have ameliorated GBIS to approximate solvation effects that explicit solvents bring about. However, the quantitative comparison of NMR structures in the latest GBIS and explicit solvents is lacking. In this study, we report the direct comparison of NMR structures that atomistic MD simulation coupled with GBIS and water molecules refined. Two model proteins, GB1 and ubiquitin, were recalculated with experimental distance and torsion angle restraints, under a series of simulated annealing time steps. Whereas the root mean square deviations of the resulting structures were apparently similar, AMBER energies, the most favored regions in Ramachandran plot, and MolProbity clash scores witnessed that GBIS-refined structures had the better geometries. The outperformance by GBIS was distinct in the structure calculations with sparse experimental restraints. We show that the superiority stemmed, at least in parts, from the inclusion of all the pairs of non-bonded interactions. The shorter computational times with GBIS than those for explicit solvents makes GBIS a powerful method for improving structural qualities particularly under the conditions that experimental restraints are insufficient. We also propose a method to separate the native-like folds from non-violating diverged structures.

Buckling Experiment of Eccentric Seismic Bracing Devices for Branch Lines (내진설계용 편심방식 가지배관 고정장치의 좌굴 실험)

  • Changsoo, Oh;Jihoon, Kim;Hasung Kong
    • Journal of the Korea Safety Management & Science
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    • v.26 no.1
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    • pp.9-14
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    • 2024
  • Restraints of Branch Lines are used as earthquake-resistant support devices for fire-fighting pipes along with sway brace devices. The central types are aligned and fixed in a straight line with center of the pipe, but the eccentric types are fixed to on side of the pipe, so a bending moment occurs. In this study, three specimens each of central type and eccentric type were installed at an angle of 45° from the vertical and a monotonic compression load of 1340N was applied. All central type samples satisfied 17.8mm of the allowable displacement, but all eccentric type samples failed to meet the target load and buckled. Therefore, when considering the performance of eccentric type restraints, both compressive load and bending moment must be considered. Even through material mechanics calculations, the yield stress of eccentric type - 3/8 inch all threaded steel bolt - exceeds 320Mpa of the allowable stress. A experiment standards need to be established for eccentric type restraints.

Solution Structure of Bovine Pancreatic Trypsin Inhibitor using NMR Chemical Shift Restraints

  • Park, Kyunglae;Wil
    • Journal of the Korean Magnetic Resonance Society
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    • v.1 no.2
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    • pp.79-94
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    • 1997
  • The solution structure of bovine pancreatic trypsin inhibitor(BPTI) has been refined by NMR chemical shift data of C${\alpha}$H using classical molecular dynamics simulation. The structure dependent part of the observable chemical shift was modeled by ring current effect, magnetic anisotropy effect from the nearby groups, whereas the structure independent part was replaced with the random coil shift. A new harmonic function derived from the differences between the observed and calculated chemical shifts was added into physical force field as an pseudo potential energy term with force constant of 250 kJmol-1 ppm-2. During the 1.5 ns molecular dynamics simulation with chemical shift restraints BPTI has accessed different conformation space compared to crystal and NOE driven structure.

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Concept Analysis of Moral Distress in Nurses (간호사의 도덕적 고뇌 개념분석)

  • Yoo, Myung-Sook
    • Journal of Korean Academy of Nursing Administration
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    • v.10 no.1
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    • pp.49-62
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    • 2004
  • purpose: The study was done to analyze the concept of moral distress in nurses. Method: The Hybrid Model was used in this study. For the theoretical phase, nursing and other literature were reviewed to analyze attributes and develop a working definition of the concept, moral distress in nurses. For the fieldwork phase, In-depth interviews were conducted with six nurses. Results: Four higher level concepts of moral distress in nurses were found; situational, cognitive, behavioral, and emotional, and 8 subscales, negative medical behavior, negative nursing behavior, excessive economic load, irrational organization administration, internal restraints, external restraints, negative behavioral responses, and negative emotional responses. Conclusion: it is necessary to develop programs of arbitration that will lessen the moral distress in nurses working in clinical practice.

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A Fundamental Study on Forecast of the Thin Plate Welding Deformation by Numerical Simulation (수치시뮬레이션에 의한 박판 용접 변형 예측에 관한 기초적 연구)

  • 김종명;박창수;김영표;방한서
    • Journal of Welding and Joining
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    • v.21 no.1
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    • pp.93-98
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    • 2003
  • For construction of steel structures, thin steel plates have been often used and welding is the main manufacturing process. However, welding processes cause some problems(welding residual stresses, welding deformations, etc.). In these problems, welding deformation is extremely harmful to the safety of structures especially. Therefore, in this study, a numerical analysis program based on large deformation plate theory has been developed to analyze and predict the welding deformation in thin plates. From the result of numerical analyse, we can find two parameters, thermal cycles and mechanical restraints affecting the welding deformation of structures. It is considered that large difference of thermal cycles and mechanical restraints in the width direction bring about welding deformation. Results of simulation have the same tendency of deformation distribution in width direction as experimental formulas.