• Journal of The Korean Society of Integrative Medicine
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• v.2 no.1
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• pp.15-21
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• 2014

Purpose : The aim of this study was to find out differences between muscle activity of quadriceps according to hip angle. Method : 40 healthy adults produced maximum isometric muscle contraction of quadriceps femoris and each part of the quadriceps femoris were measured with a surface EMG in hip joint angle of $90^{\circ}$, $135^{\circ}$, $180^{\circ}$. Result : There was no significant difference between muscle activity of vastus medialis and lateralis according to hip angle. But there was significant difference in muscle activity of rectus femoris and the muscle activity was maximum at 135 degrees of hip angle. Conclusion : In conclusion, maximum muscle activation of rectus femoris is affected by hip angle, and the findings from this study may be helpful for physical therapists in selecting hip position when instructing patients to do Q-setting exercise. So, we suggest that patients perform Q-setting exercise at 135 degrees of hip angle for the best result.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.10a
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• pp.376-380
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• 2009

Surface acoustic wave (SAW) device is widely used as a bandpass filter, a chemical or physical sensor, and an actuator. In this paper, we propose the capacitive gap measurement system with high precision through the signal processing using SAW device. The research process is mainly composed of theoretical part and experimental part. In theoretical part, equivalent circuit model was used to simulate the SAW response by the change of capacitance. In experimental part, commercialized capacitor was used to see the SAW response by the change of load capacitance. After that, gap adjustment system was made physically and the SAW response by the change of gap which caused the capacitance change was measured. And resolution and stroke was decided comparing the signal change and basic measurement noise level.

• Journal of the Korea Institute of Military Science and Technology
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• v.10 no.4
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• pp.52-61
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• 2007

Temporal and spatial variations of sea water largely affect on the pattern of underwater sound propagation. Acoustic environmental changes and their effects on underwater sound propagation in the northern part of the East Sea, which have been poorly studied mainly due to lack of observations, are investigated by analyzing the hydrographic data acquired since 1993. Severe changes in acoustic environments are associated with various physical processes such as deep convection, thermal fronts, and eddies in the northern part of the East Sea. Spatio-temporal variations of sound speed field and the layer of the maximum sound speed are categorized into six typical cases. Using a sound source of 5 kHz, acoustic transmission losses are calculated range-independently for the six typical cases. Significant differences among the patterns of transmission loss in the six cases suggest that a different tactics are required when we operate in the northern part of the East Sea.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.1
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• pp.87.1-87.1
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• 2012

We use three-dimensional magnetohydrodynamic simulations to investigate how the dynamic state of emerging magnetic field is related to the twist of field lines. Emergence of magnetic field is considered as one of the key physical process producing solar activity such as flares, jets, and coronal mass ejections. To understand these activities we have to know dynamic nature and electric current structure provided by emerging magnetic field. To demonstrate dynamic nature of field lines, we focus on the factors such as curvature of magnetic field line and scale height of magnetic field strength. These factors show that strong twist case forms two-part structure in which the central part is close to a force-free state while the outer marginal part is in a fairly dynamic state. For weak twist case, it still shows two-part structure but the tendency becomes weaker than strong twist case. We discuss how the curvature distribution affects the dynamic nature of emerging magnetic field. We also investigate electric current distribution provided by emerging field lines to show a possible relation between electric current structure and sigmoid observed in a preflare phase.

• Journal of Power System Engineering
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• v.14 no.3
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• pp.77-82
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• 2010

In general, the control valves are essential components in hydraulic systems. Structural changes within the valves remain a challenge because many parameters of valve tend to interact in terms of static and dynamic performance. Therefore, the valve characteristics is applied directly to the stability of hydraulic system. Inner structure of the valve which is used mainly in the industries is made up poppet type and spool type. This paper made a description of the method for numerical analysis and modeling of the valve with a built-in moving part of four-type. Based on the physical parameters of the valves, a numerical model of objected valve is developed using the bond graph method. It is to verified the results that the moving part of four-type has an effect on pressure and flow characteristics. Also, It is analyzed the results which has an effect on response characteristic by angular of poppet valve face and inertia variation of the valve with a built-in moving part. In the results, it is confirmed that the rising and settling time vary with the shape of moving part in valve.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.102.1-102.1
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• 2011

In this study we use three-dimensional magnetohydrodynamic simulations to investigate how the dynamic state of emerging magnetic field is related to the twist of field lines. Emerging magnetic field forms a magnetic structure on the Sun where various kinds of activity such as solar flares, jets, and coronal mass ejections are observed. To understand the physical mechanism for producing such activity, we have to know the dynamic nature of this structure. Since flares are the manifestation of rapidly dissipating electric current in the corona, we also investigate the distribution of current density inside the structure and examine how it depends on the field-line twist. To demonstrate the dynamic structure of emerging magnetic field, we focus on the factors characterizing the geometric property and stratification of emerging magnetic field, such as the curvature of field line and the scale height of field strength. These two factors show that emerging field forms a two-part structure in which the central part is close to a force-free state while the outer marginal part is in a fairly dynamic state where magnetic pressure force is dominant. We discuss how the field-line twist affects the two-part structure and also explain a possible relation between electric current structure and sigmoid observed in a preflare phase.

• Korean Journal of Optics and Photonics
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• v.6 no.4
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• pp.266-273
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• 1995

Colors reproduced by color imaging system are affected by various physical factors. The spectral response of the color image sensor is one of the important factors. We developed a spectral response characteristics measurement system which is composed of optical part and color analyzing part. The data from the optical part was analyzed by the color analyzing part and spectral response characteristics of R, G, B three color sensors were obtained. Using this system, the spectral response characteristics of a CCD color camera was measured. From this result, color rendition and linearity of the camera could be analyzed. This measurement system is $.$considered to be very useful for the evaluation of color image sensor characteristics. stics.

• Journal of Korean Physical Therapy Science
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• v.6 no.1
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• pp.897-903
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• 1999

Many out patients of the rehabilitation center complaint a pain caused by suffering of MPS, and it brings many different kind of social and ecinomical problems such as medical expenses and the reduction in work efficiency. Therefore, we conducted a research to present a fast and effective treatment to the MPS patients. this research was conducted from November, 1996 to January 1998 with eighteen outpatients who agreed to be the subjects to our reserach. We applied the electric acupuncture on 28 different trigger point on the patients with mostly muscular-skeletal pain and some tender and radiating pain. After the treatment, VRS, VAS, PRI were used to measure the degree of the pain on the patients third and seventh visits, and following results were found. 1. To apply EAP treatment, we acupunctured 6em-Iong needles on Tps region, then the electrodes of pulse generater pg-306 E.S.T were connected on the top of the needles. the electric acupuncture therapy was conducted for 20 minutes with the intensity of 4hz - 60hz(auto wave). The treated electric intensity was the level at which the patients did not feel discomfort. 2. Thirteen out of the 18 participated patients were in their 30s and 40s(72.2%), showing highest frequency. There were more female than male with the ratio of 1 to 1:2. 3. six out of the participated patients (33.3%) had the pain for less then a week, and the average duration of the pain of the participated patients wear 0.8 years. 4. The pain occured mostly in the upper trapezius by 6 part (21.4%), then in the gluteus medius region by 4 part (14.3%). Many of the patients with the pain in the upper back area accompanied varios kind of the referred pains such as radiculopathy, HIVD and Frozen shoulder. 5. MPS occured more frequently on the right side than left side then left side and it seemed to be due to the frequent use of the right hand. 6. There was almost no difference in the measurement of the intensity of the pain right before and after the EAP treatment. Howerver, there was significant decrease in the numerical values of the VAS, and a little bit of decrease in the numerical values of the PRI after the EAP treatment. 7. Based on the results of this present research, it can be concluded that EAP can be used for the treating the myofascial pain syndrome with promptness and safety in most cases.

• Korea Science and Art Forum
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• v.24
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• pp.277-287
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• 2016

This study purpose is comparative analysis of environmental design checklist based on physical characteristics of the elders between Korea and Japan exhibition facilities. We were selected to represent the exhibition facilities in Korea and Japan and conducted field survey and understand the application status. The scope of the exhibition facilities space is entry, exhibition, public-service, educational activity and movement. And the elders physical characteristics are divided into 'sense(eye-sight, hearing, and feeling by touch)' / 'exercise (skeleton, movement, physical strength and muscular strength)'. Based on the checklist, we gave the score depending installation, part installation and uninstallation and then analyzed the average. The Results were as follows. First, Korea and Japan exhibition facilities are appear to similar and both above the average level. It is show that environment design reflects the physical characteristics of the elders. Second, exhibition space and educational activity space has lower score than other space, indicated most items are consist of the recommended. Most items appears as part of the preparation for this installed or uninstalled. Third, It showed that the installation is incomplete entries corresponding to the physical characteristics of the sensory area of the elderly (hearing). Therefore, there need to install additional information facilities such as voice, emergency call bell. Forth, the exhibition facilities appears differently depending on time of erecting and remodeling.

• Journal of the Korean Ceramic Society
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• v.13 no.1
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• pp.11-19
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• 1976

This study was focused on the improvement of production techniques of small crucibles in relation with the appropriate selection of raw materials, various batch compositions and physical and chemical characteristics of the crucibles. Various tests gave the optimum batch composition for the carbon bond graphite cructble as follows: Pyontaek graphite flake (refractory aggregate) : 40Part Silicon carbide: 15Part Tar pitch (binder) : 11Part Inorganic additives (to improve the oxidation resistance) : 15 Part Cryolite : 3 Part Ferro manganese : 2 Part Ferrosilicon : 25 Part Crucibles pressed with 400kg/$\textrm{cm}^2$ at 12$0^{\circ}C$. and fired in reducing atmosphere at 120$0^{\circ}C$ brought the most favorable results as follows: Bulk density : 2.31 Apparent density : 2.58 Porosity : 15.2% Oxidation loss at 1, 50$0^{\circ}C$. for 3 hrs : below 3.77% Water absorption : 6.01% Compressive strength : 438kg/$\textrm{cm}^2$ Tensile strength : 256kg/$\textrm{cm}^2$.