• Journal of Advanced Marine Engineering and Technology
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• v.33 no.2
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• pp.259-266
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• 2009

An experimental study was conducted to investigate the effects of forcing amplitude on the flow structure near the nozzle exit of forced jet diffusion flames. The jet was excited up to the blowout occurrence by a considerable large amplitude with a periodic velocity fluctuation at the tube resonating frequency. In the attached flame regime, we disclosed the very interesting result newly that adding of a moderate forcing amplitude caused the jet flame to become longer in spite of being forced. Particular attention is focused on the turnabout mechanism of vortex roll-up around the elongated flame, which has not been reported previously, and on the inner coherent structure of the forced jet in the attached flame regime. From the velocity and flow visualization results, it was ascertained that the surrounding air due to the occurrence of negative velocity parts was suck into the fuel nozzle. To aid in understanding the rotating phenomenon of coherent structure, we present a schematic diagram of the turnabout mechanism of vortex roll-up. The mechanism of vortex turnabout phenomenon can be easily understood by considering the positive and negative velocity amplitudes about the instantaneous velocity of the forcing flow, as shown in this diagram.

• Journal of Advanced Marine Engineering and Technology
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• v.25 no.3
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• pp.563-572
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• 2001

With the results of calculation for natural frequencies the reponses of forced coupled vibration of propulsion shafting system were investigated by the modal analysis method. For the forced vibration response analysis, the axial exciting forces, the axial damper/detuner, propeller exciting forces and damping coefficients were extensively considered. As the conclusion of this study, some items are cleared as follows.-The torsional vibration amplitudes are not influenced by the radial excitation forces of the crank shaft. -The axial vibration amplitudes are influenced by the tangential exciting forces as well as the radial exciting forces of the crank shaft. The increase of the amplitudes is observed in the speed range at the neighbourhood of any torsional critical speed. 1The closer the torsional and axial critical speed. the larger coupling effect becomes. -The axial exciting force of propeller is relatively strong comparing with axial exciting forces of cylinder gas pressure and oscillating inertia of reciprocating mechanism. Therefore, the following conclusions are obtained. -Torsional vibration calculation with the classical one dimensional model is still valid. -The influence of torsional excitation at each crank upon the axial vibration is improtant. especially in the neighbourhood of a torsional critical speed. That means that the calculation of axial vibration with the classical one dimensional model is inaccurate in most of cases.

• Journal of Families and Better Life
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• v.21 no.1
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• pp.13-24
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• 2003

The purpose of this article Is to review the problems in using Hazan & Shaver,s adult attachment inventory as spousal attachment inventory. In summary, Hazan & Shaver's forced-choice inventory is required to caution in using for spouse attachment inventory because of the disproportionally higher secure-attachment type ratio(72% - 89%). It was previous reseaches that used multi-item Likert inventory instead of Hazan & shaver's forced-choice inventory for result analysis because of disproportionally higher secure-attachment type ratio. Although Hazan & shaver's forced-choice inventory was mostly used for young unmarried adults, Using Hazan & shaver's forced-choice inventory as spouse attachment inventory for married adults seem to be inappropriately. Hazan & Shaver's multi-item Likert inventory has the problem of poor reliability in insecure-avoidence factor especially. Hazan & Shaver's one item Likert inventory has the problem of social desirability.

• Journal of International Academy of Physical Therapy Research
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• v.2 no.2
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• pp.339-343
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• 2011

The purpose of this study is to see the effect of functional electrical stimulation on forced vital capacity and alternating motion rate in children with spastic cerebral palsy. This study divided 20 children with spastic cerebral palsy into two groups; functional electrical stimulation treatment group and control group. Functional electrical stimulation treatment group had 20min per day treatment three times a week for four weeks and the control group did not have any treatment. Before and after intervention, this study measured forced vital capacity and alternate motion rate(/peo/,/teo/) for all children. Forced vital capacity showed statistically significant increase for the group with functional electrical stimulation(p<.05) while the control group did not show any significant increase(p>.05). Alternate motion rate showed statistically significant increase for the group with functional electrical stimulation(p<.05) while the control group did not show any significant increase(p>.05). This result shows that functional electrical stimulation affected the ability of the children with spastic cerebral palsy who have decreased breathing and phonation capability.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.5
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• pp.467-472
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• 2004

This paper presents the normalized site attenuation characteristics for frequencies below 80 ㎒ using forced resonant type EMI dipole antennas. The coupled integral equations for unknown current distribution are solved by the Galerkin's method of moments with piecewise sinusoidal functions. The results show that the forced resonant type EMI dipole antenna for frequencies below 80 ㎒ can be used effectively for the measuring normalized site attenuation. The calculated normalized site attenuation curves for the forced resonant type EMI dipole antenna are useful in determining the suitability of open area test sites.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.29 no.6 s.237
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• pp.711-721
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• 2005

In order to design of emergency ventilation systems, the smoke movements in tunnel fire with natural and forced ventilation were investigated. Reduced-scale experiments were carried out under the Froude scaling with novel fire source consisting many wicks. Temperature profiles were measured under the ceiling and vertical direction along the center of the tunnel and poisonous gases were measured at emergency exit point in the natural ventilation case. In forced ventilation, temperature profiles were measured with various flow rate to obtain critical velocity. The results showed that the interval of emergency exit having 225m was estimated reasonably through the measurements of temperature variation and poisonous gas in the natural ventilation. In the case of forced ventilation, the temperature distribution near fire source is remarkably different from that of natural ventilation. Also, the critical velocity to prevent upstream smoke flow has the range of 0.57m/s between 0.64m/s. Finally, it was also identified that although the increase of flow rate can suppress the backward flow of smoke to upstream direction, brings about the increase of flame intensity near stoichiometric fuel/air ratio.

• Earthquakes and Structures
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• v.11 no.5
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• pp.809-822
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• 2016

Reinforced concrete buildings constitute the majority of the building stock of Turkey and much of them, do not comply the earthquake codes. Recently there is a great tendency for strengthening to heal their earthquake performance. The performance evaluations are usually executed by the numerical investigations performed in computer packages. However, the numerical models are often far from representing the real behaviour of the existing buildings. In this condition, experimental modal analysis fills a gap to correct the numerical models to be used in further analysis. On the other hand, there have been a few dynamic tests performed on the existing reinforced concrete buildings. Especially forced vibration survey is not preferred due to the inherent difficulties, high cost and probable risk of damage. This study applies both ambient and forced vibration surveys to investigate the dynamic properties of a six-story residential building in Istanbul. Mode shapes, modal frequencies and damping ration were determined. Later on numerical analysis with finite element method was performed. Based on the first three modes of the building, a model updating strategy was employed. The study enabled to compare the results of ambient and forced vibration surveys and check the accuracy of the numerical models used for the performance evaluation of the reinforced concrete buildings.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2000.11a
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• pp.99-107
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• 2000

With the results of calculation for natural frequencies, the forced reponses of coupled vibration of propulsion shafting were analysed by the modal analysis method. For the forced response analysis, axial exciting forces, axial damper/detuner, propeller exciting forces and damping coefficients were extensively investigated. As the conclusion of this study, some items are cleared as next. - The torsional amplitudes are not influenced by the radial excitation forces. - The axial vibrational amplitudes are influenced by the tangential exciting forces. An increase of amplitude is observed for the speed range in the neighbourhood of any torsional critical speed. - The coupling effect becomes larger if torsional and axial critical speed are closer together. - The axial exciting force of propeller is relatively strong, comparing with those of axial forces of cylinder gas pressure and oscillating inertia of reciprocating mechanism. Therefore, as a resume one can say, that- Torsional vibration calculation with the classical one dimension model is still valid. - The influence of torsional excitation at each crank upon the axial vibration is impotent, especially in the neighbourhood of a torsional critical speed. That means that the calculation of axial vibration with the classical one dimension model is insufficient in most of cases. - The torsional exciting torque of propeller can be neglected in most of cases. But, the axial exciting forces of propeller can not be neglected for calculating axial vibration of propulsion shafting.

• The Journal of Korean Physical Therapy
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• v.32 no.2
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• pp.75-79
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• 2020

Purpose: This study analyzed the immediate effects of intra-abdominal pressure with visual feedback on the muscle activation of the upper trapezius and sternomastoid during natural inspiration and forced inspiration in individuals with costal respiration. Methods: The eighteen individuals with upper costal breathing pattern participated in this study. Surface electromyography was used to analyze the muscle activity of the upper trapezius and sternomastoid during natural inspiration and forced inspiration before and after intra-abdominal pressure. Results: A significant difference in muscle activation was observed with the muscle type, inspiration type, and test session (p<0.05). The muscle activities of the sternomastoid and upper trapezius decreased significantly during forced inspiration after intra-abdominal pressure training (p<0.05). On the other hand, there was no significant difference during natural inspiration in both muscles (p>0.05). A comparison of the difference between the pre-test and post-test during forced inspiration revealed the upper trapezius to be significantly larger than the sternomastoid (p<0.05). No significant difference was noted during natural inspiration (p>0.05). Conclusion: The intra-abdominal pressure has positive effects on correcting the breathing patterns in individuals with costal respiration.

• Journal of the Korean Society of Tobacco Science
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• v.24 no.1
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• pp.21-26
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• 2002

This study was carried out to evaluate the effect of forced fermentation on chemical and sensory properties in burley leaf tobacco. Three process steps of burley leaf tobacco(green and redried leaves produced in 2000, and aged leaves in 1998) and four grades(BlT, B2T, C1W and C2W) of leaf for every step were used in this study. The leaves were moistened by 22% moisture content, packed under 200kg/㎥ condition and stored in chamber controlled 6$0^{\circ}C$ and 90% R.H. for 7 days. Nicotine contents in three steps of burley leaf tobacco were significantly decreased by forced fermentation. Except for aged leaf, pH values of green and redried leaves were significantly lowered. Nicotine, tar and CO contents of cigarette smoke showed little difference between cigarettes containing 23%, 26% and 29% of fermented burley leaf and controlled cigarette(containing 19% of aged burley leaf). The cigarette containing 26% of the redried and fermented leaf was significantly better taste and less irritation than controlled cigarette. The results suggest that the forced fermentation may be useful to increase the rate of burley tobacco in leaf blending and to shorten the period of storage for aging.