• Journal of the Korean Applied Science and Technology
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• v.15 no.1
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• pp.47-54
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• 1998

On contraction of the muscles, marked changes in X-ray reflections are observed, suggesting that conformational changes of contractile molecules and the movement of myosin heads during muscle contraction. The time needed to the peak tension after the onset of stimulation and the amount of peak tension depend on the number of twitch cycle. It was found that the successive twitches decreased not only the time needed to the peak tension after the onset of stimulation but also the time needed to the maximum change of the X-ray intensity. However, the difference of the time between the peak tension and the maximum intensity change($T_{i}-I_{i}$) is nearly the same at any twitch. Based on these results the causes of the decrease of $T_{i}$ and $I_{i}$, and physiological implication of $T_{i}-I_{i}$ are discussed.

• Journal of Life Science
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• v.8 no.4
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• pp.373-380
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• 1998

A considerable change observed in X-ray diffraction during the muscle contraction was that the movement of myosin head and conformational change of contractile monecules were occurred in the muscle contraction. Time slice requires tension peak after the onset of stimulation and the height of tension peak depends on the number of twitch cycle. The intensity of I$_{11}$, I$_{10}$, 143${\AA}$ reflection is measured with 5ms time resolution and is recorded in isometric tension. The peak height of I$_{11}$ and 143${\AA}$ intensity is changed after the onset of a stimulation I$_{i}$, and the length of twitch is shortened by successive twitches in the case of stimulation TI$_{i}$. On the other hand, the peak height of I$_{11}$ and 215${\AA}$ intensity starts to decrease at the 1st twitch and remains constant at low peak hight without appreciable recovery during the contraction term. In the case of uccessive twitch stimulation, the myosin heads of muscle are once moved from their resting position and never returned to their initial position.

• Journal of Acupuncture Research
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• v.21 no.2
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• pp.183-203
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• 2004

Objective : Tension-type headache is the most common headache. The objective of this study is to find the clinical manifestation of tension-type headache and correlation with autonomic bioelectric response. Methods : This observation was carried out on 60 patients with tension-type headache. We used headache questionnaire and the Autonomic Bioelectric Response recoder(ABR-2000) for this study. Results : 1. Distribution of sex & age : male : female=5 : 7, 50s&60s group (28.3%) 2. Duration of onset : over 5years(50%), over one years(83.4%) 3. Causes of illness : stress(58.3%), severe fatigue(53.5%), tension(33.3%) 4. Time of attack : irregular(56.7%), day time(16.7%) 5. Pattern of pain: heavy(31 people), stiffness of occipital region (27 people) tightening around the head(25 people) 6. Curve : 40%, 56.7%, 35.0% SL(Slope low) at peak 1, 2, 3/ SH&SI not found 7. Regulation : 16.7% RR(Regulation reverse) at peak 1, 25% RH(Regulation high) at peak 2, 15% RR(Regulation reverse) at peak 3 8. Graph : Activity-60.0%, 70.0%, 63.3% lowered reaction(L, LR, L!) at peak 1, 2, 3 Reactivity-83.3%, 95.0%, 93.3% lowered reaction at peak 1, 2, 3 Conclusion : We find tension-type headache has remarkable relativeness with autonomic bioelectric response.

• Journal of the Korean Applied Science and Technology
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• v.21 no.2
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• pp.182-189
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• 2004

On contraction of the muscles, marked changes in X-ray reflections are observed, suggesting that conformational changes of contractile molecules and the movement of myosin heads during muscle contraction. Time slice requires tension peak after the onset of stimulation and the height of tension peak depends on the number of twitch cycle. The muscles were stimulated by five successive stimuli at an interval of 80 ms started while the tension was still being exerted by the muscles. The intensity of $I_{11}$, $I_{10}$, $143{\AA}$ and $215{\AA}$ reflection measured with 5ms time resolution and is recorded in isometric tension. The peak height of $I_{11}$ and $143{\AA}$ intensity is changed after the onset of a stimulation $I_i$, and the length of twitch is shortened by successive twitches in the case of stimulation $T_i$. On the other hand, the peak height of In and $215{\AA}$ intensity starts to decrease at the 1st twitch and remains constant at low peak height without appreciable recovery during the contraction term. In the case of successive twitch stimulation, the myosin heads of muscle are once moved from their resting position and never returned to their initial position.

• The Korean Journal of Pharmacology
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• v.13 no.2
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• pp.11-17
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• 1977

The effects of varing concentrations of extracellular potassium on the positive inotropic actions of Aconiti tuber butanol fraction and ouabain were studied on isolated left atrium of rat. The patterns of active tension increment, such as time to peak and total duration of tension development, was contrasted in Aconiti tuber butanol fraction to ouabain. Ouabain did not induce significant shortening in time to peak and total duration of tension development, but Aconiti tuber produce significant shortening. The isometric tension and peak dF/dt were not significantly different at the range of extracellular potassium concentration $2mEq{\sim}10mEq$ per. liter in control studies. The ouabain-induced increase in active tension and peak dF/dt at 2mEq. per. liter potassium concentration was significantly different from that of 6mEq or 10mEq. per. liter, but there was no difference between 6mEq and 10mEq. per. liter. but Aconiti tuber is not. In contrast to ouabain, Aconiti tuber butanol fraction did not show potassium dependent positive inotropic effect. It produced almost same increment of tension and peak dF/dt at all the concentration of extracellular potassium concentrations in this experiment.

• Journal of Ocean Engineering and Technology
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• v.7 no.1
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• pp.124-132
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• 1993

In order to examine the effect of anisotropy and stress ratio on fatigue crack propagation rate and opening-closing behavior and also arrest behavior by single tension peak overload, the fatigue tests of constant amplitude atress and single tension peak overload adding to cycle of constant amplitude were carried out in stress ratio of -0.4, -0.2, and 0.4 with materials of T-L and L-T directions in 2024-T3 aluminum alloy plate. Crack opening-closing begavior were measured by the compliance method using COD gage and strain gage. In case of the crack opening-closing behavior was measured by strain gage, the effect of stress ratio is unchangeable. But in the case of COD gage, that is remarkably decreased. Fictitious effective stress intensity factor(U sub(f)) and effective stress intensity factor ratio(U) in L-T direction was higher than those in T-L direction and also threshold arrest overload ratio incrased as stress ratio decreased and that of T-L direction was higher than that in L-T direction.

• Transactions of the Korean Society of Automotive Engineers
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• v.4 no.1
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• pp.123-133
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• 1996

From the experimental study of wire-cut Electric Discharge Machining of alloyed tool steel and tungsten carbide, the characteristics such as cutting speed, surface roughness has been observed and evaluated for various conditions. Cutting speed is improved as peak discharge current and wire tension become increased, and gap voltage and spark cycle decreased. Surface roughness can be better when peak discharge current and gap voltage become smaller, or spark cycle and wire tension become larger. Secondary cut is recommended to obtain high precision and good quality.

• Structural Engineering and Mechanics
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• v.83 no.4
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• pp.435-449
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• 2022

Constitutive modeling that could reasonably predict and effectively evaluate the post-peak structural behavior while eliminating the mesh-dependency in numerical simulation remains to be developed for general engineering applications. Based on the previous work, a simple one-dimensional modeling procedure is proposed to predict and evaluate the post-peak response, as characterized by the evolution of localized strain field, of a steel member to monotonically uniaxial tension. The proposed model extends the classic one-dimensional softening with localization model as introduced by (Schreyer and Chen 1986) to account for the localization length, and bifurcation and rupture points. The new findings of this research are as follows. Two types of strain-softening functions (bilinear and nonlinear) are proposed for comparison. The new failure criterion corresponding to the constitutive modeling is formulated based on the engineering strain inside the localization zone at rupture. Furthermore, a new mathematical expression is developed, based on the strain rate inside and outside the localization zone, to describe the displacement field at which bifurcation occurs. The model solutions are compared with the experimental data on four low-carbon cylindrical steel bars of different lengths. For engineering applications, the model solutions are also compared to the experimental data of a cylindrical steel bar system (three steel bars arranged in series). It is shown that the bilinear and nonlinear softening models can predict the energy dissipation in the post-peak regime with an average difference of only 4%.

• Journal of Biosystems Engineering
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• v.17 no.3
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• pp.237-246
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• 1992

This study was conducted to investigate experimentally the effect of track tension on the tractive performance of rice combine. The experiment was carried out at the two in-door soil bins with soil types of loam and sandy loam. The initial track tension was varied by three different values of 0.71, 1.75 and 3.84kN at three different forward velocity settings of 0.17, 0.32 and 0.45m/s, respectively. The data acquisition system was designed and used for the measurement of pull, driving axle torque and its velocity under the test conditions to calculate the tractive efficiency. Results of the study were summarized as follows : 1) The effect of the initial track tension on the tractive efficiency was found being significantly dependent on soil types but not on forward velocities. Therefore, the benifit of adjusting the initial track tension may be obtained when the types of soils on which combines operate are changed. 2) In loam, tractive efficiency decreased with increase in track tension. However, it increased in sandy loam until it reached to a peak value and then decreased with increase in track tension. 3) The maximum tractive efficiency of the tested combine was obtained with an initial track tension of about 1.75kN on sandy loam, and below that on loam at about 5% slippage without being noticeably influenced by the forward velocity.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2004.05a
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• pp.55-60
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• 2004

In this study, the configuration and tension of a towing cable for side-scan sonar are predicted in an ambient flow and at an unsteady towing condition. The governing equation of three-dimensional dynamic analysis for a flexible cable is solved using a finite difference method. We successfully predict the configuration and tension of a side-scan sonar and designed the towing system. It is found in static analyses that the side-scan sonar must be towed to keep a its stable depth at a reasonable speed. The study also reveals in the transient analyses that the dominant component affecting the top tension is the tangential drag force for the larger towing speed than the critical speed, and the self weight of a towed instrument for the smaller towing speed than. It should be maneuvered for a towing vessel with good consideration for the impact effect in a cable due to tension peak when a towing speed is suddenly increase. The developed program can be applicable for three-dimensional dynamic analysis of a towing system for various marine survey instruments.