• Journal of Korean Academy of Fundamentals of Nursing
• /
• v.7 no.2
• /
• pp.301-315
• /
• 2000

The main purpose of this study was to evaluate the effect of a Rhythmical Exercise Program(REP) on physiological functions such as muscle strength, blood pressure, pulse, flexibility and body fat in the elderly. The research employed a non-equivalent control group pre-post test quasi experimental design. REP consisted of 45 minutes of dance, 3 times a week for 10 weeks. The formulated hypothesis were examined using the non-parametric statistics; Wilcoxon Signed rank sum test and Mann-Whitney test. The results are as follows; 1. The upper muscle strength and lower muscle strength of the experimental group were significantly higher than those of the control group following the REP(P<.0 5). And the Period of REP affected the muscle strength; the longer the exercise period, the stronger the muscle strength became. 2. The systolic blood pressure of the experimental group was significantly lower than that of the control group following the REP(p<.05). But there was no significant difference in the diastolic blood pressure between the experimental and control groups. The period of REP affected only systolic pressure; the longer the exercise period, the lower the systolic pressure became. 3. There was no significant difference in heart rate between the experimental and control groups, following the exercise period. 4. The flexibility of the experimental group was significantly higher than those of the control group following the REP(p<.01). And the period of REP affected flexibility; the longer the exercise period, the higher the flexibility(p<.05) became. 5. There was no significant difference of body fat between the experimental and control groups. The body fat of the experimental groups was significantly lower only 10 weeks after exercise(p<.01). Based on these results, it is suggested that rhythmical exercise program improves muscle strength, systolic pressure, and flexibility in the elderly.

• Journal of the Korean Society for Precision Engineering
• /
• v.28 no.7
• /
• pp.805-813
• /
• 2011

The dynamic stress of the diesel engine block is analyzed by using flexible-body dynamic analysis. Multiple loadings including the pressure load due to gas combustion, thermal load, and dynamic load are considered. Thermal load is assumed constant, however, pressure load and dynamic load are treated as time dependent. The present work is focused on the dynamic stress analysis, especially on finding critical points of the engine block. The analysis model includes four parts - engine block, generator, bed, and mounts. On the other hand, crank shaft, pistons, and main bearings are excluded from the model. However, their dynamic effects are applied by dynamic forces, obtained in the separate analysis. Dynamic stress is found by using flexible body dynamic analysis, and compared to the measured data.

• Smart Structures and Systems
• /
• v.28 no.6
• /
• pp.839-853
• /
• 2021

In this paper, a novel multimode liquid metal-based pressure sensor is developed. The main body of the sensor is composed of polydimethylsiloxane (PDMS) elastomer. The structure of the sensor looks like a sandwich, in which the upper structure contains a cylindrical cavity, and the bottom structure contains a spiral microchannel, and the middle partition layer separates the upper and the bottom structures. Then, the liquid metal is injected into the top cavity and the bottom microchannel. Based on linear elastic fracture mechanics, the deformation of the microchannel cross-section is theoretically analyzed. The changes of resistance, capacitance, and inductance of the microchannel under pressure are deduced, and the corresponding theoretical models are established. The theoretical values of the pressure sensor are in good agreement with experimental data, implying that the developed theoretical model can explain the performance of the sensor well.

• Journal of IKEEE
• /
• v.26 no.2
• /
• pp.249-256
• /
• 2022

The prosthetic leg is a device that performs walking instead of a amputated lower limb, and require a change in locomotion mode by providing the user's intention to respond to a discontinuous locomotion environment. Research has been conducted to detect the users' intentions through biomechanical features inside the socket that directly contacts the cut site in demand for natural locomotion mode changes without external control equipment. However, there is still a need for a sensor system that is suitable for the internal environment of the main body and socket of the cut site. Accordingly, this paper proposed a film-type sensor system that is suitable for the main body characteristics of the cut site, is not affected by the temperature and humidity conditions inside the socket, and is easy to manufacture in various sizes. The proposed sensor is manufactured base on Velostat film and takes into account the pressure measurement characteristics that vary with size. Through the experiment, the change in the internal pressure of the socket due to the intentional posture performance of the wearer was measured, and the possibility of detecting the intention to change the locomotion mode was confirmed.

• Proceedings of the KSME Conference
• /
• 2001.06a
• /
• pp.871-876
• /
• 2001

One-touch fittings are important components that can make a quick and tight connection between pneumatic pipe systems. In this study, the stress analyses with various working pressures on these one-touch fittings are carried out using finite element method. Material properties, to use the stress analyses, are measured by the universal tester and digital Vickers hardness tester. The stress analyses on the circular shell spring forced by various pressures(100, 150, 200, 250kpa) and on the main body due to the fluid-structural interaction are investigated. Results show that the stresses of one-touch fitting are concentrated to supported part of main body and the soundness of a circular shell spring with maximum pressure 250kpa was confirmed.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.30 no.1
• /
• pp.40-46
• /
• 2016

Many medicinal plants have been used for the treatment of edema, jaundice, and gonorrhea in traditional Oriental medicine. This screening study was designed to search the positive inotropic effects of herbal extracts in beating rabbit atria. Aquarius extracts of twenty six herbs were examined in atrial mechanical dynamics such as pulse pressure and stroke volume and atrial natriuretic peptide (ANP), one of the main hormones involved in the regulation of the body fluid and blood pressure homeostasis in perfused beating rabbit atria. Sophora flavescens Ait., Rheum officinale Baill., Acorus gramineus Sol., Chelidonium majus L., Pulsatilla koreana Nakai., Reynoutria japonica Houtt., Euphorbia lathyris L., Pyrrosia lingua (Thunb.) Farwell, Poncirus trifoliata Rafin., Anemarrhena asphodeloides Bunge, Kochia scoparia Schrad. significantly increased stroke volume and pulse pressure. However, those herbal extracts were not induced ANP secretion. We clarified the eleven herbal extracts for the positive inotropic effect independent of ANP secretion in beating rabbit atria. Thus these results provide a beneficial data for the treatment of the impairment of body fluid and blood pressure in traditional Oriental medicine.

• Journal of the East Asian Society of Dietary Life
• /
• v.15 no.3
• /
• pp.271-282
• /
• 2005

This study analyzed the physical indices, food habits and nutrient intakes of patients with hypertension, to provide better research data for the prevention and the cure for disease as well as basic data for nutrition education. The subjects were 44 patients who visited the general hospital, located in Daegu, to receive hypertension treatment The lifestyle, food habit, nutrient intakes, anthropometric measurements, body fat and blood pressure were measured as main indices. By the BMI, $72.8\%$ of the patients were over weight or obesity $(>23\;kg/m^2)$. In the male group, the WHR tended to increase according to the BMI (p<0.05). In the female group, the body fat tended to increase according to the BMI (p<0.05). The group with more monthly income showed lower systolic blood pressure than the group with smaller monthly income (p<0.05). The scores about food habits concerning balanced diet and preference for salt were low, which implied that food habits of subjects were not desirable. The intakes of riboflavin and calcium didn't meet the RDA requirements. Especially, the lack of calcium was more ap~nt in the female patients than the male ones. Despite this, they had more than enough protein, vitamin C, and iron. The physical indices according to blood pressure revealed that the group of higher blood pressure showed greater WHR (p<0.001). The male group with higher systolic blood pressure showed greater BMI than one with lower systolic blood pressure (p<0.05). As for nutrient intakes according to blood pressure, the group with higher blood pressure had more sodium and iron than one with lower blood pressure (p<0.05). The patients with hypertension tended to be more overweight or obese, preferred salty foods, and were in an unbalanced state of nutrient intakes. Thus more systematic and ongoing measures should be pursued to take care of patients with hypertension.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2007.05a
• /
• pp.24-29
• /
• 2007

Low-speed Diesel Engine, 7K60MC-S, in Power Plant have been experienced high vibration frequently since these units were completed the construction works, but they did not have any fundamental vibration solutions up to date. Therefore, several vibration tests and analyses are conducted to identify the root cause of high vibration and to suggest the optimal countermeasures for diesel engine. The 9.25Hz & 25.4Hz vibrations have been observed on main body during operation. The magnitude of engine upper structural vibration is generally similar in horizontal transverse direction. However, differences in the 'Fore' and 'After' vibration magnitude at 9.25Hz occurs due to the inertia momentum added by SCR duct system with the same vibration phase angle. It is analyzed that the excess structural vibration be occurred when the natural frequency of engine body is accessed the exciting sources due to the explosion pressure and the discharge pulsation of 7 cylinders in resonance range.

• 유체기계공업학회:학술대회논문집
• /
• 2005.12a
• /
• pp.448-453
• /
• 2005

Temperature Control Valve (TCV) is one of the useful temperature control devices, which is used to control constant temperature of working fluid in power and chemical plants and domestic water supply systems. TCV is composed of body, cylinder and piston, and the body shape has a symmetrical H-type. In general, it has several inlet and outlet holes, and its shape is like as tubular sleeve. The piston has three rings two rings of the end of piston have the function of controlling inlet flow rate with hot and cold working fluids, the center ring has the function of preventing hot and cold water from intermixing. Consequently, the shapes of piston and cylinder are the main design parameters in the performance of TCV. In this study, numerical analyses were carried out with two different piston and cylinder shapes to investigate the functions as a temperature control valve and the flow characteristics according to piston opening grade in TCV. Using a commercial code, FLUENT, velocity and pressure fields in TCV are obtained under steady, standard $k -{\epsilon}$ turbulence model and no-slip condition.

• Journal of Hydrogen and New Energy
• /
• v.20 no.3
• /
• pp.179-187
• /
• 2009

This paper presents a static and dynamic characteristics of the relief valve which is a kind of direct operated pressure control valve for hydrogen compressor. The valve is consisted of a main poppet, a spring, an adjuster and a valve body. The purpose of this study is development of the simulation model for relief valve by using commercial AMESlM$^{(R)}$ tool. Poppet with sharp edge seat type and ball poppet with sharp edge seat type compare for P-Q characteristic. The dynamic simulation results are presented the operating pressure characteristics of relief valve. High pressure power unit of which maximum pressure control range is 100MPa was manufactured, and the pressure control valve was experimented using the above-mentioned power unit. The new model of pressure control valve from this results was suggested. It was confirmed that the suggested valve has a good control performance from experimental setup.