• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.2
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• pp.54-61
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• 2013

Stay cable has a strong axial rigidity due to large initial tension and, on the other hand, it has a weak laterally flexural rigidity. Wind loads or traffic loads cause the cables to vibrate significantly and affect the mechanical properties and the performance of cables of cable-stayed bridge (CSB). Therefore, the development of vibration reduction design is an urgent task to control the vibration vulnerable long-span bridges. As Friction damper (FD) shows to reduce the amplitude and duration time of vibration of cable of CSB from measured date in field test, friction damper can be considered that it is effective device significantly to reduce the amplitude and duration time in vibration of cable of CSB under traffic load, wind load and so on. Vibration characteristics of cable can change according to manufacturing method and type of established form. Nevertheless, analysis method in this study can present the design of friction damper for vibration reduction of cable of cable-stayed bridge from now on.

• Journal of the Korea Society for Simulation
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• v.19 no.1
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• pp.13-22
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• 2010

This paper describes tagline PD control for reduction of motion for the heavy cargo(load) suspended by a floating crane. The equations of motion are set up considering the 6-degree-of-freedom floating crane and the 6-degree-of-freedom load based on multi-body system dynamics. The tagline mechanism is applied to floating crane to control motion of the heavy cargo(load). The winch, mounted on the deck of floating crane, is used to control the tension of tagline. To generate control force, PD control algorithm is applied. Numerical simulation and experiment is executed to verify the tagline control mechanism. The numerical simulation and experiment shows that the tagline control mechanism reduces the motion of the load suspended by a floating crane.

• Archives of Plastic Surgery
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• v.39 no.5
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• pp.457-462
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• 2012

Background The elasticity of the back skin of the rat reduced the tension around wounds during the wound healing process in that region, and thus activates wound contraction. The authors proposed two skin fixation methods using readily available materials to decrease the influence of wound contraction on wound healing and designed an experiment to determine their effects. Methods The authors made 36 skin wounds on the backs of 18 rats, and they divided them into three groups. Each group was treated with three different kinds of dressing materials, each with different skin fixing characteristics. Group A was a control group. Group B and group C were dressed by the first and the second skin fixation method. We measured the areas of the wounds post-surgically and calculated the wound area reduction rates. Results The two skin fixation methods both reduced the effect of wound contraction compared to the control group. Each of the two methods had different outcomes in reducing wound contraction. Conclusions The experiment demonstrated significant differences among the wound areas and the wound area reduction rates of the three groups as a result of differences in the degree of wound contraction. To obtain accurate results from wound healing experiments, appropriate skin fixation methods must be adopted.

• Proceedings of the Korean Biophysical Society Conference
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• 2003.06a
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• pp.23-23
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• 2003

It has been suggested that the impairment of smooth muscle cell (SMC) function by alterations in the $Ca^{2+}$-activated $K^{+}$ ( $K_{Ca}$ ) channels accounts for the reduction in coronary reserve during left ventricular hypertrophy (LVH). However, this hypothesis has not been fully investigated. The main goal of this study was to assess whether the properties of $K_{Ca}$ channels in coronary SMCs were altered during LVH. New Zealand white rabbits (0.8-1.0 kg) and Sprague-Dawley rats (300-400 g) were randomly selected to receive either an injection of isoproterenol (300 $\mu\textrm{g}$/kg body weight) or an equal volume of 0.9％ saline (1 mL/kg body weight). The animals developed LVH 10 days after injection. In patch-clamp experiments, the unitary current amplitude and open probability for the $K_{Ca}$ channels were significantly reduced in LVH patches compared with control patches. The concentration-response curve of the $K_{Ca}$ channel to [C $a^{2+}$]$_{i}$ was shifted to the right. Inhibition of the $K_{Ca}$ channels with TEA was more pronounced in LVH cells than in the control cells. The whole-cell currents of $K_{Ca}$ channels were reduced during LVH. Western blot analysis indicated no differences in $K_{Ca}$ channel expression between the control and LVH coronary SM membranes. In contraction experiments, the effect of a high $K^{+}$concentration on the resting tension of the LVH coronary artery was greater than on that of the control. The effect of TEA on the resting tension of the LVH coronary artery was reduced as compared with the effect on the control. Our findings imply a novel mechanism for reduced coronary reserve during LVH.ing LVH.

• Journal of the Korean Society of Physical Medicine
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• v.18 no.4
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• pp.97-107
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• 2023

PURPOSE: This study aimed to explore the effect of applying elastic taping and passive stretching exercises simultaneously on the muscle tone of the upper trapezius. METHODS: Thirty healthy adults were randomly divided into two groups: the 'passive stretching exercise' group (n = 15) and the 'passive stretching exercise with elastic taping' group (n = 15). Muscle tone was measured using the MyotonPRO®. The muscle tension was measured immediately after the stretching exercises and taping intervention, and again 5 minutes after the intervention. RESULTS: Within each group, there was a significant reduction in muscle tone in the upper trapezius after treatment (p < .05). However, there was no significant difference in the muscle tone reduction between the groups (p > .05). Both experimental and control groups showed a significant decrease in muscle tone in both the upper trapezius muscles over time, i.e., immediately after treatment and five minutes later (p < .05). The main effect of time was identified in the repeated measures analysis, while there was no main effect attributed to the treatment method (group) (p < .05). CONCLUSION: The simultaneous application of stretching exercises and taping as an intervention to reduce muscle tension in the upper trapezius is still considered challenging and not yet widely regarded as an essential intervention method.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.10
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• pp.865-871
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• 2014

Paradigm shift to 3-D chip stacking in electronic packaging has induced a lot of integration challenges due to the reduction in wafer thickness and pitch size. This study presents a hybrid bonding technology by self-alignment effect in order to improve the flip chip bonding accuracy with ultra-thin wafer. Optimization of Cu pillar bump formation and evaluation of various factors on self-alignment effect was performed. As a result, highly-improved bonding accuracy of thin wafer with a $50{\mu}m$ of thickness was achieved without solder bridging or bump misalignment by applying reflow process after thermo-compression bonding process. Reflow process caused the inherently-misaligned micro-bump to be aligned due to the interface tension between Si die and solder bump. Control of solder bump volume with respect to the chip dimension was the critical factor for self-alignment effect. This study indicated that bump design for 3D packaging could be tuned for the improvement of micro-bonding quality.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2004.11a
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• pp.18-34
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• 2004

This paper will review data obtained primarily from our preclinical investigations that show that exposure to stress has a significant impact on drug taking. Stress increases reward associated with psychomotor stimulants, possibly through a process similar to sensitization, and a growing clinical literature indicates that there is also a link between substance abuse and stress in human addicts. One explanation for the high concordance between stress-related disorders and drug addiction is the self-medication hypothesis, which suggests that a dually-diagnosed person often uses the abused substance to cope with tension associated with life stressors or to relieve symptoms of anxiety and depression resulting from a traumatic event. However, another characteristic of drug self-administration is that drug delivery and its subsequent effects on the HPA axis are under the direct control of the individual. This controlled activation of the HPA axis may result in the production of an internal state of arousal or stimulation that is actually sought by the individual (i.e., the sensation-seeking hypothesis). During abstinence, however, exposure to stressors or drug-associated cues can stimulate the HP A axis to remind the individual about the effects of the abused substance, thus producing craving and promoting relapse. Stress reduction, either alone or in combination with pharmacotherapies targeting the HPA axis may prove beneficial in reducing cravings and promoting abstinence in individuals seeking treatment for addiction. Of primary importance is to reduce the impact of cocaine-associated environmental stimuli on the HPA axis so that they no longer function as triggers for relapse.

• Archives of Plastic Surgery
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• v.32 no.4
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• pp.496-502
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• 2005

This study was performed to compare the effect of external ultrasound assisted PAL(power assisted liposuction) with that of PAL alone. We performed 17 cases of liposuction from January 2003 to June 2003. For comparing both systems, we treated the right side(study group) with external ultrasound assisted PAL and the left side(control group) with PAL alone. To evaluate the difference in results between two groups, we surveyed three objective and four subjective items. Objectives were categorized as "Reduction rate of postoperative swelling", "Efficiency of suction" and "Histologic finding of aspirated fat tissue". Subjectives were also filed as "Degree of postoperative bruising", "Cannula resistance that operator felt", "Degree of postoperative pain" and "Patient's satisfaction". We assessed by questionnaire three times at 1day, 7 days and 30 days after operation. There were statistically significant differences in two of the subjective items; "Degree of postoperative pain at postoperative 1 day" and "Cannula resistance that operator felt". This study concludes that external ultrasound PAL is more effective high mobility of fat tissue and low tension of surrounding tissue. External ultrasound PAL will be more useful in case of large volume liposuction and revision procedures.

• BMB Reports
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• v.40 no.6
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• pp.1009-1015
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• 2007

In this communication, we report the efficacy of $\beta$-carotene towards differentiation and apoptosis of leukemia cells. Dose ($20{\mu}M$) and time dependence (12 h) tests of $\beta$-carotene showed a higher magnitude of decrease (significance p < 0.05) in cell numbers and cell viability in HL-60 cells than U937 cells but not normal cell like Peripheral blood mononuclear cell (PBMC). Microscopical observation of $\beta$-carotene treated cells showed a distinct pattern of morphological abnormalities with inclusion of apoptotic bodies in both leukemia cell lines. When cells were treated with $20{\mu}M$ of $\beta$-carotene, total genomic DNA showed a fragmentation pattern and this pattern was clear in HL-60 than U937 cells. Both the cell lines, on treatment with $\beta$-carotene, showed a clear shift in $G_1$ phase of the cell cycle. In addition the study also revealed anti-oxidant properties of $\beta$-carotene since there was reduction in relative fluorescent when treated than the control at lower concentration. Collectively this study shows the dual phenomenon of apoptosis and differentiation of leukemia cells on treatment with $\beta$-carotene.

• Computers and Concrete
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• v.19 no.4
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• pp.339-346
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• 2017

The main objective of this paper was to illuminate the effect of marine environmental condition on durability of reinforced concrete (RC)-corroded columns strengthened with carbon fiber reinforced polymer (CFRP) and glass fiber reinforced polymer (GFRP) layers. Small-scale columns were prepared and corroded by an accelerated corrosion process. After strengthening, compressive strength tests were carried out on control and weathered specimens. In this research, a marine simulator was designed and constructed similar to the tidal zone of marine environment in south of Iran which was selected as a case study in this research. Mechanical properties of wrapped specimens were studied after placing them inside the simulator for 3000 hours. Marine environment decreased ultimate strength by 4.5% and 26.3% in CFRP and GFRP-wrapped columns, respectively. In some corroded-columns, strengthening was carried out after replacing damaged cover by self-compacted mortar. In this method, by confining with one layer of CFRP and GFRP, 4.2% and 22.4% reduction in ultimate strength was observed, respectively, after exposure. Furthermore, the elastic-brittle behavior has been verified in this retrofit method. Also results of tension tests revealed, the ultimate tensile strength was degraded by 2% and 28.8% in CFRP and GFRP sheets, respectively, after applying marine exposure.