• Title/Summary/Keyword: internal force

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Socio-Economic Aspects of the Impact of Military Actions on the Labor Force

  • Melnyk, Stepan;Petrukha, Nina;Shuprudko, Nataliia;Ilychok, Bohdan;Balanutsa, Oleksandr
    • International Journal of Computer Science & Network Security
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    • v.22 no.7
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    • pp.252-258
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    • 2022
  • Ukraine has a significant in quantity and unique in quality parameters, in particular, the level of education, a resource - the labor force, which, along with natural resources, can serve as the basis for economic growth and the achievement of sustainable development goals. The study is aimed at a thorough identification of the main factors influencing the formation and use of the labor force in Ukraine, including by comparing with the indicators of the EU countries, before the start of the active phase of military aggression by the Russian Federation. It was found that until February 24, 2022, there were negative trends in the change in the quantitative and qualitative indicators of the labor force due to the demographic crisis, the transformation of the national economy and shortcomings in state regulation of labor market development processes. The military actions not only exacerbated pre-existing problems, but also led to the emergence of new ones. A significant number of refugees and internally displaced persons, with the termination of the activities of half of the economic entities, provoked a sharp increase in real unemployment and a decrease in wages. The specific problem of the labor market of Ukraine - the "labor crisis", which has and will have a significant impact on the labor force, is carefully considered.

Experimental investigation of friction in expansion zone of tube hydroforming with material and lubricant (튜브 액압성형 공정의 확관영역에서 소재 및 윤활에 따른 마찰 특성의 실험적 연구)

  • Lee, G.Y.;Yim, H.S.;Lee, S.M.;Yi, H.K.;Chung, G.S.;Moon, Y.H.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2008.10a
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    • pp.359-362
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    • 2008
  • In this study, friction test was proposed to obtain coefficient of friction between tube and die in expansion zone of tube hydroforming and friction coefficients were evaluated at different materials, viscosity of lubricants and internal pressures. For this study, STKM11A and SUS tubes were prepared. The tube was expanded by an internal pressure against the tool wall. The tube was expanded by an internal pressure against the tool wall. By pushing the tube through the tool, a friction force at the contact surface between the tube and the tool occurs. From the measured geometries and FE analysis, the friction coefficients between tube and die at the expansion zone in tubular hydroforming can be estimated. The effects of the various internal pressures, viscosity of lubricants, tube materials and tube thickness on friction coefficients are discussed.

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The effect of internal axial forces of a cantilever beam with a lumped mass at its free end

  • Zhang, Jinfu
    • Coupled systems mechanics
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    • v.7 no.3
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    • pp.321-331
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    • 2018
  • When a cantilever beam with a lumped mass at its free end undergoes free transverse vibration, internal axial forces are produced in the beam. Such internal axial forces have an effect on free transverse vibration of the beam. This effect is studied in this paper. The equations of motion for the beam in terms of the generalized coordinates including the effect are derived. The method for determining free transverse vibration of the beam including the effect is presented. In numerical simulations, the results of free transverse vibration of the free end of the beam including and not including the effect are obtained. Based on comparison between the results obtained, the conclusions concerning the effect are given.

Strategies for Management of the Early Chronic Obstructive Lung Disease

  • Lee, Jung Yeon;Rhee, Chin Kook;Jung, Ki Suck;Yoo, Kwang Ha
    • Tuberculosis and Respiratory Diseases
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    • v.79 no.3
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    • pp.121-126
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    • 2016
  • Lung function reportedly declines with age and that this decline is accelerated during disease progression. However, a recent study showed that the decline might peak in the mild and moderate stage. The prognosis of chronic obstructive pulmonary disease (COPD) can be improved if the disease is diagnosed in its early stages, prior to the peak of decline in lung function. This article reviews recent studies on early COPD and the possibility of applying the U.S. Preventive Services Task Force recommendation 2008 and 2015 for early detection of COPD in Korea.

Frequency analysis of beams with multiple dampers via exact generalized functions

  • Failla, Giuseppe
    • Coupled systems mechanics
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    • v.5 no.2
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    • pp.157-190
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    • 2016
  • This paper deals with frequency analysis of Euler-Bernoulli beams carrying an arbitrary number of Kelvin-Voigt viscoelastic dampers, subjected to harmonic loads. Multiple external/internal dampers occurring at the same position along the beam axis, modeling external damping devices and internal damping due to damage or imperfect connections, are considered. The challenge is to handle simultaneous discontinuities of the response, in particular bending-moment/rotation discontinuities at the location of external/internal rotational dampers, shear-force/deflection discontinuities at the location of external/internal translational dampers. Following a generalized function approach, the paper will show that exact closed-form expressions of the frequency response under point/polynomial loads can readily be derived, for any number of dampers. Also, the exact dynamic stiffness matrix and load vector of the beam will be built in a closed analytical form, to be used in a standard assemblage procedure for exact frequency response analysis of frames.

Experimental Studies of the Forming Process for the Tubular Hydroforming Technology (관재 하이드로 포밍에 의한 성형 공정의 실험적 연구)

  • 김성태;임성언;이택근;김영석
    • Transactions of Materials Processing
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    • v.9 no.1
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    • pp.35-42
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    • 2000
  • In this paper, we developed the hydroforming simulator which can apply an axial compressive force and high internal pressure to bulge a tube. Experimental dtudies have been performed to investigate the effect of each parameters such as internal pressure and axial compression stroke required for the forming of circular components. Under the improper forming conditions there were two forming failures. One was the axial buckling due to excessive axial compressive load and the other was the circumferential necking fracture due to relatively high internal pressure. A safe forming zone without any failures exists between these two extreme zones. Also the condition of forming failure such as fracture is examined throughout the theoretical analysis. This paper covers a brief overview of the mechanism of hydroforming process as well as the design of die and tools.

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Shape optimization of a bow for maximizing internal-energy (내부에너지를 최대로 하는 활 구조의 최적화)

  • Moon, Myeong-Jo;Lee, Hyun-Jung
    • Proceeding of EDISON Challenge
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    • 2016.03a
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    • pp.222-227
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    • 2016
  • In this paper, the optimized design for bow structure was investigated by using EDISON software. Considering the mechanism of the bow, non-linear FEM analysis was essential. The factors of the design are height, width, number of holes and taper value. High performance of the internal energy and lowest mass were main issues. The limit of the von-mises stress was yield strength for the material. Material was chosen by considering typical bow material, Aluminum. Using Taguchi method($L_9$), 9 models were selected and contribution rate was calculated for each factors. Following the contribution rate, 3 factors were fixed and optimized model was predicted. After making optimized model for FEM analysis, the value of internal-energy, mass for FEM model were compared with predicted value, calculated the percentage error and figure out the reliability of Taguchi method.

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Influence of Target Manufacturing Condition on the Coercive Force and Effective Permeability of Permalloy (타게트 제조조건이 퍼멀로이 박막의 보자력 및 투자율에 미치는 영향)

  • 김현태;김상주;한석희;김희중;강일구;김인응
    • Journal of the Korean Magnetics Society
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    • v.4 no.4
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    • pp.319-325
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    • 1994
  • Permalloy films were deposited by an RF magnetron sputtering method using several different targets which had been cold-rolled and annealed at various temperatures to give different microstructure and texture. The grain refinement occurs at high temperature annealing due to recrystallization and subsequently the initial (110) target texture transforms to the random texture. The coercive forces of thin films fabricated using targets which are not recrystallized are below 0.2 Oe in the AI pressure range of 1~5 mTorr and the lowest coercive force achieved is 0.07 Oe. The low value of coercive force, 0.25 Oe, is only obtained at the sputtering conditions of 400 W and 1 mTorr, and 300 W and 5 mTorr when recrystallized targets are used. The internal stress changes from compressive to tensile as the Ar pressure increases, the stress-free being at 5 mTorr. The changes of coercive force and permeability can be well interpreted by the differences from the composition and the internal stress.

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Introduction of Sunu Manual Therapy ; Principle, Technique (선우정골요법의 소개 : 원리, 시술방법)

  • Park, Tae-Yong;Yang, Na-Rae;Do, Kwang-Sun;Sunu, Yoon-Young
    • The Journal of Churna Manual Medicine for Spine and Nerves
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    • v.12 no.1
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    • pp.71-81
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    • 2017
  • Objectives : It is important to develop a new Chuna manual therapy as a representative of Chuna manual therapy technique at the time of KSCMM's (Korean Society of Chuna manual medicine) joining a $F{\acute{e}}d{\acute{e}}ration$ Internationale de $M{\acute{e}}decine$ Manuelle (FIMM). Therefore, Sunu manual therapy (SMT) will be introduced as a purely new Chuna manual therapy. Main subject : Sunu manual therapy (SMT) was discovered about two decade ago by a Korean Medicine doctor who wanted to develop a new manual therapy to treat a internal disease. It is very important to make the best use of four powers such as a compression force, a torsion force, a bending force, a tension force using a resonance principle and to experience a feeling of spine axis. SMT is different from Chiropractic technique and Osteopathy technique, in that SMT could treat so many disease using only one technique, but other manual therapy could utilize so many technique to treat only one disease. Discussion : Because SMT utilize a power of a moving in silience, it will take several years to totally master a SMT which will make a patient and a doctor experience a feeling of spine axis. As a feeling of spine axis is deeper, a nerve could be excited and treated by a SMT. Also as a feeling of spine axis is shallower, a muscle could be excied and treated by a SMT. Conclusions : SMT could be classed as a craniosacral chuna therapy or visceral chuna therapy to treat a internal disease considering SMT's action and purpose.

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Shear strength analyses of internal diaphragm connections to CFT columns

  • Kang, Liping;Leon, Roberto T.;Lu, Xilin
    • Steel and Composite Structures
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    • v.18 no.5
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    • pp.1083-1101
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    • 2015
  • Previous theoretical equations for the shear capacity of steel beam to concrete filled steel tube (CFT) column connections vary in the assumptions for the shear deformation mechanisms and adopt different equations for calculating shear strength of each component (steel tube webs, steel tube flanges, diaphragms, and concrete etc.); thus result in different equations for calculating shear strength of the joint. Besides, shear force-deformation relations of the joint, needed for estimating building drift, are not well developed at the present. This paper compares previously proposed equations for joint shear capacity, discusses the shear deformation mechanism of the joint, and suggests recommendations for obtaining more accurate predictions. Finite element analyses of internal diaphragm connections to CFT columns were carried out in ABAQUS. ABAQUS results and theoretical estimations of the shear capacities were then used to calibrate rotational springs in joint elements in OpenSEES simulating the shear deformation behavior of the joint. The ABAQUS and OpenSEES results were validated with experimental results available. Results show that: (1) shear deformation of the steel tube dominates the deformation of the joint; while the thickness of the diaphragms has a negligible effect; (2) in OpenSEES simulation, the joint behavior is highly dependent on the yielding strength given to the rotational spring; and (3) axial force ratio has a significant effect on the joint deformation of the specimen analyzed. Finally, modified joint shear force-deformation relations are proposed based on previous theory.