• Journal of the Korean Society of Manufacturing Process Engineers
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• v.4 no.4
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• pp.39-47
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• 2005

In this paper, a novel high power micropump using active check valves in place of conventional passive check valves employed at the inlet and outlet ports is presented. It actively controls open/close motion of check valves using piezoelectric actuator for expansion/contraction of pump chamber. A prototype micropump having an effective size of $17mm{\times}8mm{\times}11mm$ is fabricated. Frequency-dependent flow rate characteristics, bi-directional flow characteristics and load characteristics are experimentally investigated using a timing control method for valve closing motion. From the obtained experimental results, it is ascertained that optimal values of the phase shift compared to the voltage to drive pump chamber are $15^{\circ}$ for inlet check valve and $195^{\circ}$ for outlet. Based on the obtained results, a sheet-type active shuttle valve that has a unified valve-body for inlet and outlet check valves is proposed. A micropump with an effective size of $10mm{\times}10mm{\times}10mm$ is fabricated and the basic characteristics are experimentally investigated.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1864-1869
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• 2003

A novel piezoelectric micropump using active check valves in place of conventional passive check valves in inlet and outlet has been proposed and investigated. It actively controls open/close motion of check valves using piezoelectric actuator for expansion/contraction of pump chamber. In this paper, bi-directional flow characteristics and load characteristics are experimentally investigated using an adequate timing control for valve closing motion with a prototype micropump fabricated with the effective size of $17{\times}8{\times}11mm^{3}$. From the experimental results, it is ascertained that optimal values of phase shift against voltage to drive pump chamber for realization of a miniaturized but powerful micropump, are $15^{\circ}$ in inlet check valve and $195^{\circ}$ in outlet. Based on the obtained results, a sheet-type active shuttle valve that has a unified valve-body for inlet and outlet check valves is proposed. A micropump with the effective size of $10{\times}10{\times}10mm^{3}$ is fabricated and basic characteristics are experimentally investigated.

• Journal of Naturopathy
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• v.11 no.2
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• pp.152-157
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• 2022

Background: There have been no reports of studies on the effect of a combination of myofascial relaxation technique and passive stretching on the lower extremity body shape of working women. Purpose: This study aimed to examine the effects of myofascial relaxation technique and passive stretching on body composition and body composition analysis (intracellular fluid, skeletal muscle mass, body cell mass), etc. Methods: The subjects of this study were 30 women at a body shape management center who had many problems with their subjective lower extremity body shape. Fifteen subjects were in the experimental group and the control group. The experimental group applied the fascial relaxation technique twice a week for nine weeks. The control group conducted stretches by themselves at least twice a week according to the active stretching instructions. The ANOVA program analyzed the data. Results: In the experimental group, intracellular fluid (p < .05), skeletal muscle mass (p < .048), and body cell mass (p < .047) were significantly increased. Conclusion: The lower extremity edema of working women decreased

• Structural Monitoring and Maintenance
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• v.5 no.2
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• pp.297-311
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• 2018

Plate and shell structure is widely applied in engineering, i.e. building roofs, aircraft wings, ship platforms, and satellite solar arrays. Its vibration problem has become increasingly prominent due to the tendency of lightening, upsizing and flexibility. As a new smart material with great actuating force and toughness, macro-fiber composite (MFC) is composed of piezoelectric fiber and epoxy resin basal body, which can be directly pasted onto the surface of plate and shell and is suitable for vibration control. This paper deduces the actuation equation of MFC coupled plate in different boundary conditions, an equivalent finite element modeling method is proposed which uses MFC actuating force as the applied excitation, and on this basis the active control simulation and experiment of MFC over plate and shell structure vibration are accomplished. The results indicate that MFC is able to implement effective control over plate and shell structure vibration in multi-band range. The comparison between experiment and simulation proves that the actuation equation deduced herein, effective and practicable, can be applied into the simulation calculation of MFC vibration control over plate and shell structure.

• Osong Public Health and Research Perspectives
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• v.9 no.6
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• pp.289-298
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• 2018

Objectives: To describe the distribution of social factors, lifestyle habits and anthropometric measurements according to hypertension and Type-2 diabetes. Methods: A cross-sectional study was conducted in Gaza City, Palestine that included 379 patients (20-60 years) who had hypertension and/or diabetes. Three groups of patients were involved; 106 hypertensive (HT), 109 diabetic (T2DM) and 164 hypertensive diabetics (HT + T2DM). Results: The HT + T2DM group were older and had a higher body mass index compared to HT and T2DM groups. There were 62.3% patients who were female, 49.2% were highly educated HT patients, and 49.3% patients had a low level of education and were HT + T2DM. There were 55.8% patients who lived in large families. Patients who were passive smokers or never smoked before were mostly HT + T2DM, while active smokers and past smokers had T2DM. There were 48.2% patients who were highly physically active who had HT, 40.9% whom were moderately active had T2DM, and 53.8% of patients who had a low level of activity were HT + T2DM. Multivariate linear regression showed that having a diseased mother, living in a large family, being a past or passive smoker, or never having smoked, having a low or moderate level of activity, and having HT or HT + T2DM, were significantly associated with an increased body mass index. Conclusion: Parental health/disease conditions and environmental factors (social network and lifestyle habits) played the greatest role in the development of obesity and disease.

• Journal of Korean Academy of Nursing
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• v.43 no.3
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• pp.352-360
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• 2013

Purpose: In this study an examination was done of the effects of the American Society of PeriAnesthesia Nurses (ASPAN) Evidence-Based Clinical Practice Guidelines on body temperature, shivering, thermal discomfort, and time to achieve normothermia in patients undergoing total knee replacement arthroplasty (TKRA) under spinal anesthesia. Methods: This study was an experimental study with a randomized controlled trial design. Participants (n=60) were patients who underwent TKRA between December 2011 and March 2012. Experimental group (n=30) received active and passive warming measures as described in the ASPAN's guidelines. Control group (n=30) received traditional care. Body temperature, shivering, thermal discomfort, time to achieve normothermia were measured in both groups at 30 minute intervals. Results: Experimental group had slightly higher body temperature compared to control group (p=.002). Thermal discomfort was higher in the experimental group before surgery but higher in the control group after surgery (p=.034). It decreased after surgery (p=.041) in both groups. Time to achieve normothermia was shorter in the experimental group (p=.010). Conclusion: ASPAN's guidelines provide guidance on measuring patient body temperature at regular intervals and on individualized and differentiated hypothermia management which can be very useful in nursing care, particularly in protecting patient safety and improving quality of nursing.

• Journal of muscle and joint health
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• v.2 no.2
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• pp.131-146
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• 1995

Many arthritis patients experience weakness of muscles in extremities mainly due to disuse atrophy and weight gain because of the limited activities and exercises. This study examines the effects of the 6-week aquatic-exercise program on the body fat and the muscle of the rheumatoid arthritis patients. Seventeen patients in the experimental group and 18 in the control group were assigned depending on their preference and physical condition. These patients had more than 3 points of pain out of 10, deformities in knee, wrist and ankle joints. The amount of aquatic exercise increases from 35 minutes in the first week to 60 minutes in the 6th week. In the resting period they discussed their own experiences about exercise, personal and family affairs, and performed some recreation programs in order to increase the self-efficacy and promote the relationship with other patients by the group activities. Skinfold thickness and circumferences of both extremities were measured before and after experiment to compare the difference. For testing the body fat Saham Model was used. Prior to the experiment two group's body weight, skinfold thickness and skin circumferences were not significantly different which indicates the homogeneity of two groups. Body weight and most parts of skinfold thickness of the experimental group were significantly lower than the control group after 6-week aquatic exercise program. Circumference was not significantly lower than the control after the program. These findings indicate the in-crease of muscle sizes and the reduction of the body fat. Therefore a more active application of aquatic exercise into a variety of clients is strongly suggested.

• Journal of Mechanical Science and Technology
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• v.20 no.11
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• pp.1823-1833
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• 2006

An immune algorithm is a kind of evolutional computation strategies, which is developed in the basis of a real immune mechanism in the human body. Recently, scientific or engineering applications using this scheme are remarkably increased due to its significant ability in terms of adaptation and robustness for external disturbances. Particularly, this algorithm is efficient to search optimal parameters against complicated dynamic systems with uncertainty and perturbation. In this paper, we investigate an immune algorithm embedded Proportional Integral Derivate (called I-PID) control, in which an optimal parameter vector of the controller is determined offline by using a cell-mediated immune response of the immunized mechanism. For evaluation, we apply the proposed control to mitigation of vibrations for nonlinear structural systems, cased by external environment load such as winds and earthquakes. Comparing to traditional controls under same simulation scenarios, we demonstrate the innovation control is superior especially in robustness aspect.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.6
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• pp.1381-1388
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• 1993

This paper presents a method for the simultaneous optimal design of structural and control systems. Sensitivities of performance index with respect to structural design variables are analyzed. The structural design variables are optimized to minimize the performance index by use of conjugate gradient method. The method is applied to a half model of an active vehicle suspension system with elastic body moving on a randomly profiled road. The suspension control force of an optimally controlled system in the presence of measurement errors are calculated by use of linear quadratic Gaussian control theory and Kalman filter theory. The performance index contains ride comfort, road holding and working space of suspension. The structural design variables taken are stiffness, daming properties and the position of the suspension system. The random road profile considered as colored noise is shaped from white noise by use of shaping filter. The performance of an optimal simultaneous structure/control system is compared with that of an optimal controlled system.

• Ocean Systems Engineering
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• v.13 no.4
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• pp.401-421
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• 2023

Reducing hawser line tensions and dynamic responses to a certain level is of paramount importance as the hawser lines provide important structural linkage between 2 body TLP-TAD system. The objective of this paper is to demonstrate how MR Damper can be utilized to achieve this. Hydrodynamic coefficients and wave forces for two bodies including second-order effects are obtained by 3D diffraction/radiation panel program by potential theory. Then, multi-hull-riser-mooring-hawser fully-coupled time-domain dynamic simulation program is applied to solve the complex two-body system's dynamics with the Magneto-Rheological (MR) Damper modeled on one end of hawser. Since the damping level of MR Damper can be changed by inputting different electric currents, various simulations are conducted for various electric currents. The results show the reductions in maximum hawser tensions with MR Damper even for passive control cases. The results also show that the hawser tensions and MR Damper strokes are affected not only by input electric currents but also by initial mooring design. Further optimization of hawser design with MR Damper can be done by active MR-Damper control with changing electric currents, which is the subject of the next study.