• Proceedings of the KIEE Conference
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• 1989.07a
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• pp.401-404
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• 1989

Some magnetic probes for theta-pinch experiment have been constructed. Methods of building the coil, conecting it to the oscilloscope, shielding and enclosing the probe are discribed. Such a probe has been used to measure the magnetic flux penetrating it within theta - pinched plasmas.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.7
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• pp.717-722
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• 2012

This paper presents the design and dynamic model of the finger exoskeleton actuated by Ionic Polymer Metal Composites (IPMC) to assist a tip pinch task. Although this exoskeleton will be developed to assist 3 degree-of-freedom motion of each finger, it has been currently made to perform the tip pinch task using 1 degree-of-freedom mechanism as the first step. The six layers of IPMC were stacked in parallel to increase the low actuation force of IPMC. In addition, the finger dummy was manufactured to evaluate the performance of the finger exoskeleton. The pinch task experiments, which were performed on the finger dummy with the developed exoskeleton, showed that the pinch force close to the desired level was obtained. Moreover, the dynamic model of the exoskeleton and finger dummy was developed in order to perform the various analyses for the improvement of the exoskeleton.

• Journal of the Korea Institute of Military Science and Technology
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• v.24 no.2
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• pp.211-218
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• 2021

This paper deals with the computational work to characterize the formation and pinching of a plasma in an X-pinch configuration. A resistive magnetohydrodynamic model of a single fluid and two temperature is adopted assuming a hollow conical structure in the (r,z) domain. The model includes the thermodynamic parameter of tungsten from the corrected Thomas-Fermi EOS(equation of state), determining the average ionization charge, pressure, and internal energy. The transport coefficients, resistivity and thermal conductivity, are obtained by the corrected Lee & More model and a simple radiation loss rate by recombination process is considered in the simulation. The simulation demonstrated the formation of a core-corona plasma and intense compression process near the central region which agrees with the experimental observation in the X-pinch device at Seoul National University. In addition, it confirmed the increase in radiation loss rate with the density and temperature of the core plasma.

• BMB Reports
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• v.46 no.4
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• pp.230-235
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• 2013

Nephrin, a structural molecule, is also a signaling molecule after phosphorylation. Inhibition of nephrin phosphorylation is correlated with podocyte injury. The PINCH-1-ILK-${\alpha}$-parvin (PIP) complex plays a crucial role in cell adhesion and cytoskeleton formation. We hypothesized that nephrin phosphorylation influenced cytoskeleton and cell adhesion in podocytes by regulating the PIP complex. The nephrin phosphorylation, PIP complex formation, and F-actin in Wistar rats intraperitoneally injected with puromycin aminonucleoside were gradually decreased but increased with time, coinciding with the recovery from glomerular/podocyte injury and proteinuria. In cultured podocytes, PIP complex knockdown resulted in cytoskeleton reorganization and decreased cell adhesion and spreading. Nephrin and its phosphorylation were unaffected after PIP complex knockdown. Furthermore, inhibition of nephrin phosphorylation suppressed PIP complex expression, disorganized podocyte cytoskeleton, and decreased cell adhesion and spreading. These findings indicate that alterations in nephrin phosphorylation disorganize podocyte cytoskeleton and decrease cell adhesion through a PIP complex-dependent mechanism.

• The Journal of Korean Physical Therapy
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• v.32 no.4
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• pp.198-202
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• 2020

Purpose: This study examined the effects of a paraffin treatment with exercise on the muscle strength and fatigue of the hand according to the use of smartphones. Methods: The measurement subjects were 30 healthy males in their 20s who were divided randomly into the control and paraffin treatment groups. A typing exercise using a smartphone was performed. The pinch grip force was measured to evaluate the muscle strength of the thumb, and muscle fatigue analysis using electromyography was performed to analyze muscle fatigue. Results: The functional changes to the arm and the fatigue of the hand through the use of a smartphone were examined to determine the effects of the paraffin treatment. The dominant hand-pinch grip force test did not show a significant difference, but the non-dominant hand-pinch grip force test showed a significant difference between the groups (p=0.030). In the dominant hand fatigue test, there was a significant difference between the groups (p=0.037). In the non-dominant hand, there was a significant difference between time (p=0.012) and the groups (p<0.001). Conclusion: The effects of paraffin intervention on the hand muscle strength and fatigue due to repeated use of the smartphone were confirmed. These results can be used as a basis for clinical use and can be a guide for the correct use of smartphones, which are essential in modern life.

• Journal of the Korean Society of Visualization
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• v.20 no.3
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• pp.10-18
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• 2022

We present an experimental investigation on emulsions created during the impact process between a surfactant-laden droplet and an oil layer on water. By varying the surfactant concentration and the viscosity of oil layer, we created emulsions and visualized them using multi-dimensional high-speed imaging. Our analysis shows that the emulsions are more likely to be unstable and decay within a minute if the impacting droplet contains more surfactant. We also found that there are three mechanisms of generation of emulsions depending on the concentration of surfactant and the viscosity of oil layer; the jet pinch-off, cavity pinch-off, and tearing of oil layer. Jet and cavity pinch-off turned out to be dominant mechanisms for high oil viscosities, while tearing of oil layer is dominant for low oil viscosities. Our result is potentially useful in designing optimal dispersant properties for offshore oil contamination.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.4
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• pp.301-308
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• 2015

In this paper, we propose an LTBC (Low Tension and Load Balance Control) scheme to improve a coiling shape control by reduction the tension fluctuation by the torque disturbance in the down coiler process of hot strip mills. The proposed controller is a combination of an LTC to control the overload at load-on in the mandrel and an LBC to regulate the load balance of the upper and bottom pinch roll. A tension calculation model is suggested with the concept of the tension deviation. The effectiveness of the proposed control scheme is verified from simulation under a disturbance of the pinch roll torque. Using a field test, we show that the performance of the shape and tension control is improved by the LTBC control.

• Journal of Chest Surgery
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• v.51 no.5
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• pp.333-337
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• 2018

Background: Pinch-off syndrome (POS) is a rare complication after totally implantable venous access device (TIVAD) implantation. In cancer patients, it is important to prevent this rare complication and to recognize it early if it does occur. We present a case series of POS after TIVAD implantation and the results of a literature search about this complication. Methods: From July 2006 to December 2015, 924 permanent implantable central venous catheter implantation procedures were performed. The most common indication was vascular access for chemotherapy. Results: POS occurred in 5 patients in our clinic. Two patients experienced POS within 2 weeks, and the other 3 patients were admitted to department of surgery, Istanbul Faculty of Medicine at 6 to 14 months following implantation. The catheters were found to be occluded during medication administration, and all patients complained of serious pain. The transected fragments of the catheters had migrated to the heart. They were successfully removed under angiography with a single-loop snare. Conclusion: POS is a serious complication after TIVAD implantation. It is important to be aware of this possibility and to make an early diagnosis in order to prevent complications such as drug extravasation and occlusion events.

• Physical Therapy Rehabilitation Science
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• v.4 no.2
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• pp.61-65
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• 2015

Objective: The aim of this study was to objectively evaluate sensory disturbance in cervical spondylosis using grip force and investigate the relationship between the grip force and upper extremity function. Design: Cross-sectional study. Methods: Eleven cervical spondylosis patients with paresthesia conducted grip and lift tasks using a precision grip with the tips of the thumb and index finger on either side. The sum of the grip force used during the first four seconds was calculated and defined as the total grip force. The cutaneous pressure threshold of the fingers, the pinch power, the grip power and three subtests of the Simple Test for Evaluating Hand Function (STEF) were also assessed. Correlations between the total grip force and cutaneous pressure threshold, pinch power, grip power, and STEF subtest times were evaluated. Results: We found that the total grip force correlated with the cutaneous pressure threshold (p<0.05). Moreover, the total grip force of the dominant thumb correlated with the results of the three STEF subtests (p<0.05). There were no significant correlations between the total grip force and pinch/grip powers. Conclusions: We found that the total grip force correlated with cutaneous pressure threshold and upper extremity function. The results suggest that the total grip force could serve as an objective index for evaluating paresthesia in cervical spondylosis patients, and that the impaired ability of the upper extremity function is related to grip force coordination.

• Korean Journal of Adult Nursing
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• v.17 no.2
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• pp.298-309
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• 2005

Purpose: The purpose of this study was to investigate the effect of a comprehensive rehabilitation program on grip strength, pinch strength, the shoulder joint function, flexibility, and fatigue in mastectomy patients. Method: The subjects were fifty-five women with breast cancer (27 in the control group and 28 in the experimental group). The subjects in the experimental group participated in a comprehensive rehabilitation program for 10 weeks, which was composed of education, stress management, exercise, and peer support group activity. Results: The results revealed that the increase in grip strength, key pinch, the shoulder joint function, and flexibility (Back & Reach test, Standing & Bending reach test) of the operated extremity, and the decrease in fatigue were significantly higher in the experimental group than in the control group. However, the results revealed that tip strength and palmar pinch of the experimental group increased but there was no significant difference from that of the control group. Conclusions: The 10-week comprehensive rehabilitation program showed much affirmative effect on physical function, and fatigue of breast cancer patients after mastectomy.