• The Journal of the Acoustical Society of Korea
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• v.41 no.5
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• pp.557-563
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• 2022

The cortical bone thickness of the tibia is related to fracture risk and overall bone status. The present study aims to investigate the feasibility of two different ultrasonic methods for measuring the cortical bone thickness in bovine tibia in vitro. In the reflection technique, the tibial cortical thickness was determined from ultrasonic reflections from the periosteum and the endosteum producing specific peaks in the signal envelope. In the axial transmission technique, the tibial cortical thickness was determined from ultrasonic guided wave velocities measured along the axial direction of the tibia. The cortical bone thickness determined by using the reflection technique correlated significantly with that measured by using a caliper, with a Pearson's correlation coefficient of r = 0.97 (p < 0.0001). In contrast, the correlation coefficients for the axial transmission technique were r = 0.92 (p < 0.0001) for the first arriving signal method and r = 0.89 (p < 0.0001) for the slow guided wave method. Clinical feasibility should be demonstrated with an in vivo application to address the question whether the ultrasonic methods presented here could be useful as a screening tool for osteoporosis and potentially could be applied to other skeletal sites such as the femur and the radius.

• Journal of Haehwa Medicine
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• v.23 no.1
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• pp.57-69
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• 2014

This study is based on "Hoesamgyeong(會三經)", the interpretation of the Lecture on Truth of "Samilshingo(三一神誥:Korea's national scripture)". And the goal of this study is to arrange theoretical system of Korean traditional qigong training by doing research on the principles of qigong that are contained in Yookdaesungsang(六大成象) on the basis of Traditional Korean Medicine. Yookdaesungsang(六大成象) is the ideas that appeared for the first time in "Hoesamgyeong(會三經)". Yookdaesungsang(六大成象) refers to Kong(空), Yol(熱), Jin(震), Seup(濕), Han(寒) and Ko(固), which mean six elements of nature. And they correspond with Sung(性), Myoung(命), Jung(精), Sim(心), Ki(氣) and Shin(身) respectively, which are fundamental components of human beings according to the Lecture on Truth of "Samilshingo(三一神誥)". This has a thread of connection with the ideas of 'the unity of nature and human beings(天人合一)' or 'the correspondence between nature and human beings(天人相應)' in Traditional Korean Medicine. From the standpoint of modern science, what are more tangible such as Seup(濕), Han(寒), and Ko(固) are considered as changes in states of matter by activities, while what are relatively intangible such as Kong(空), Yol(熱), and Jin(震) are regarded as wave energy. And in the ideas of three yin(三陰) and three yang(三陽), on which the meridian system of Traditional Korean Medicine is based, Taeyang(太陽)-Soeum(少陰), Yangmyung(陽明)-Taeeum(太陰), and Soyang(少陽)-Gweoleum(厥陰) are respectively ins and outs of the human body and they keep the balance between yin and yang such as cold(寒)-hot(熱), dry(燥)-wet(濕), and slow(緩)-fast(急). As these cold(寒)-hot(熱), dry(燥)-wet(濕), and slow(緩)-fast(急) correspond with Han(寒)-Yol(熱), Jin(震)-Seup(濕), and Kong(空)-Ko(固), the correlation between Yookdaesungsang(六大成象) and the meridian system can be ascertained. As mentioned above, the principles of Qigong in "Hoesamgyeong(會三經)" are based on traditional ideas and accord closely with the principles of Traditional Korean Medicine. Therefore, further researches on the correlations between principles of Qigong unique to Korean tradition and Traditional Korean Medicine are required.

• The Korean Journal of Physiology
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• v.9 no.1
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• pp.45-56
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• 1975

Various factors influencing the lymph flow from thoracic duct were investigated in an attempt to evaluate their contributing degree and the mechanisms. Sixteen mongrel dogs weighing between 10 and 16 kg were anesthetized and polyethylene catheters were inserted into the thoracic duct and femoral veins. Arterial blood pressure, heart rate, central venous pressure, lymph pressure and lymph flow were measured under various conditions. Electrical stimulation of left sciatic nerve, stepwise increase of central venous pressure, manual application of rhythmical depressions onto abdomen, injection of hypertonic saline solution and histamine infusion were employed. Measurement of cental venous pressure was performed through the recording catheter inserted into abdominal inferior vena cava. Changes in central venous pressure were made by an air-ballooning catheter located higher than the tip of the recording catheter in the inferior vena cava. Lymph flow from thoracic duct was measured directly with a graduated centrifuge tube allowing the lymph to flow freely outward through the inserted cannula. The average side pressure of thoracic lymph was $1.1\;cmH_2O$ and lymph flow was 0.40 ml/min or 1.9 ml/kg-hr. Hemodynamic parameters including lymph flow were measure immediately before and after (or during) applying a condition. Stimulation of left sciatic nerve with a square wave (5/sec, 2 msec, 10V) caused the lymph flow to increase 1.4 times. The pattern of lymph flow from thoracic duct was not continuous throughout the respiratory cycle, but was continuous only during Inspiration. Slow and deep respiration appeared to increase the lymph flow than a rapid and shallow respiration. Relationship between central venous pressure and the lymph flow revealed a relatively direct proportionality; Regression equation was Lymph Flow (ml/kg-hr)=0.09 CVP$(cmH_2O)$+0.55, r=0.67. Manual depressions onto the abdomen in accordance with the respiratory cycle caused the lymph flow to increase most remarkably, e.g,. 5.5 times. The application of manual depressions showed a fluctuation of central venous pressure superimposed on the respiratory fluctuation. Hypertonic saline solution (2% NaCl) administered Intravenously by the amount of 10 m1/kg increased the lymph flow 4.6 times. The injection also increased arterial blood pressure, especially systolic Pressure, and the central venous pressure. Slow intravenous infusion of histamine with a rate of 14-32 ${\mu}g/min$ resulted in a remarkable increase in the lymph flow (4.7 times), in spite of much decrease in the blood pressure and a slight decrease in the central venous pressure.

• International Commerce and Information Review
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• v.13 no.2
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• pp.75-94
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• 2011

This study is designed to expand 'Q-Methodology' into the global marketing realm in attempt to find out how Canadian consumers will perceive Korean food. The ultimate aim of this thesis is to lay a basic foundation to globalize Korean food and heighten the potential and quality of Korean food. Korean food, well-known as slow diet, jumps on the bandwagon of the Korean Wave and spreads at a rapid pace. At this point, most Korean food becomes widespread under the influence of the boom of not just the Korean Wave but also the growing desire for health food. Hence, it is the most important to analyze consumers' types in order to learn how each individual nation perceives Korean Food. This can be used as the basic research and study to enhance the national competitiveness of Korean food. Q-methodology is adopted in this study to reveal the critical dimensions and characteristics of the target market and/or consumers for Korean Food using the Canadian respondents' subjective attributes. Three categories (pragmatic trend type, traditional culture seeking type, a beginner type) of Canadian consumer behavior regarding Korean Food are found and suggested in this study. The objective attributes of Korean food are not considered here, but the Canadian consumers' subjective behavioral attributes are.

• Korean Journal of Remote Sensing
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• v.34 no.6_3
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• pp.1383-1398
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• 2018

Sea surface wind is one of the most fundamental variables for understanding diverse marine phenomena. Although scatterometers have produced global wind field data since the early 1990's, the data has been used limitedly in oceanic applications due to it slow spatial resolution, especially at coastal regions. Synthetic Aperture Radar (SAR) is capable to produce high resolution wind field data. KOMPSAT-5 is the first Korean satellite equipped with X-band SAR instrument and is able to retrieve the sea surface wind. This study presents the validation results of sea surface wind derived from the KOMPSAT-5 backscattering coefficient data for the first time. We collected 18 KOMPSAT-5 ES mode data to produce a matchup database collocated with buoy stations. In order to calculate the accurate wind speed, we preprocessed the SAR data, including land masking, speckle noise reduction, and ship detection, and converted the in-situ wind to 10-m neutral wind as reference wind data using Liu-Katsaros-Businger (LKB) model. The sea surface winds based on XMOD2 show root-mean-square errors of about $2.41-2.74m\;s^{-1}$ depending on backscattering coefficient conversion equations. In-depth analyses on the wind speed errors derived from KOMPSAT-5 backscattering coefficient data reveal the existence of diverse potential error factors such as image quality related to range ambiguity, discrete and discontinuous distribution of incidence angle, change in marine atmospheric environment, impacts on atmospheric gravity waves, ocean wave spectrum, and internal wave.

• The Korean Journal of Physiology and Pharmacology
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• v.18 no.5
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• pp.383-390
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• 2014

Gastrointestinal motility consists of phasic slow-wave contractions and the migrating motor complex (MMC). Eupatilin (Stillen$^{(R)}$) has been widely used to treat gastritis and peptic ulcers, and various cytokines and neuropeptides are thought to be involved, which can affect gastrointestinal motility. We performed a study to identify the effects of eupatilin on lower gastrointestinal motility with electromechanical recordings of smooth muscles in the human ileum and colon. Ileum and colon samples were obtained from patients undergoing bowel resection. The tissues were immediately stored in oxygenated Krebs-Ringer's bicarbonate solution, and conventional microelectrode recordings from muscle cells and tension recordings from muscle strips and ileal or colonic segments were performed. Eupatilin was perfused into the tissue chamber, and changes in membrane potentials and contractions were measured. Hyperpolarization of resting membrane potential (RMP) was observed after administration of eupatilin. The amplitude, AUC, and frequency of tension recordings from circular and longitudinal smooth muscle strips and bowel segments of the ileum and colon were significantly decreased after admission of eupatilin. Eupatilin elicited dose-dependent decreases during segmental tension recordings. In conclusion, eupatilin (Stillen$^{(R)}$) showed inhibitory effects on the human ileum and colon. We propose that this drug may be useful for treating diseases that increase bowel motility, but further studies are necessary.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.10a
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• pp.231-239
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• 2009

The filtered-x LMS (FX-LMS) algorithm has been applied to the active noise control (ANC) system in an acoustic duct. This algorithm is designed based on the FIR (finite impulse response) filter, but it has a slow convergence problem because of a large number of zero coefficients. In order to improve the convergence performance, the step size of the LMS algorithm was modified from fixed to variable. However, this algorithm is still not suitable for the ANC system of a short acoustic duct since the reference signal is affected by the backward acoustic wave propagated from a secondary source. Therefore, the recursive filteredu LMS algorithm (FU-LMS) based on infinite impulse response (IIR) is developed by considering the backward acoustic propagation. This algorithm, unfortunately, generally has a stability problem. The stability problem was improved by using an error smoothing filter. In this paper, the recursive LMS algorithm with variable step size and smoothing error filter is designed. This recursive LMS algorithm, called FU-VSSLMS algorithm, uses an IIR filter. With fast convergence and good stability, this algorithm is suitable for the ANC system in a short acoustic duct such as the intake system of an automotive. This algorithm is applied to the ANC system of a short acoustic duct. The disturbance signals used as primary noise source are a sinusoidal signal embedded in white noise and the chirp signal of which the instantaneous frequency is variable. Test results demonstrate that the FU-VSSLMS algorithm has superior convergence performance to the FX-LMS algorithm and FX-LMS algorithm. It is successfully applied to the ANC system in a short duct.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1445-1456
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• 2011

This paper presents the research of Low Pass Filter(hereinafter called "LPF") which is the part of Chopper Gate Control Unit on the electric rolling stock. Chopper Gate Control Unit controling the propulsive equipments of electric rolling stock consists of several electronic parts, PCB, Power Supply, Gate Circuit Amp, Freon Cooling Device, and has been used the parts made by japan manufacturer Mitsubish. But these parts recently have been more broken down and slow down performance because of long-term use, deterioration. Most of the malfunctions are low performance of LPF. Furthermore, it is physically impossible to repair LPF. Because it is molding type part and no longer manufactured. Also it needs high cost for custom-building. Therefore, it is now making up for through self-developed LPF and operating on Busan metro 1st after on-board testing. This research performed the PS Pice simulation testing, analysis of self-developed LPF performance and the wave form characteristic by multi-function synthesizer, spectrum analyzer, oscilloscope.

• Journal of Life Science
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• v.12 no.4
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• pp.375-382
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• 2002

The purpose of this experiment was to examine influence of acute exercise on nocturnal sleep which had been disrupted by caffeine(400mg$\times$3) thought the daytime. Six healthy young males aged 21.0$\times$0.2 yr with a history of low caffeine use. Subjects completed three conditions in a within-subject. At three conditions Sleep EEG were investigated: (1) nocturnal following quiet rest, (2) nocturnal sleep following the consumption of 1200mg of caffeine (3) nocturnal sleep following cycling at 60 min of 60% V $O_{2peak}$ with 1200mg of caffeine consumption. Sleep data were calculated for REM sleep, REM latency, sleep onset latency, sleep efficiency, sleep stages, SWS. Those data were analyzed using repeated-measures ANOVA of change scores. A main effect to, drug(caffeine) indicated that caffeine elicited sleep disturbance that is, TST and sleep onset latency increase and sleep efficiency and stage 4 decrease. The effects of exercise on sleep following caffeine intake generally improve sleep that is, stage 2, 3 and SWS increase and sleep onset latency decrease. A condition effect for sleep indicated sleep improvement after exercise Therefore The data supported a restorative theory of slow-wave sleep and suggest that acute exercise may be useful in promoting sleep and reducing sleep disturbance elevated by a high dose of caffeine.

• Journal of the Korea Convergence Society
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• v.9 no.4
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• pp.119-125
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• 2018

The purpose of this study is to analyze the 'Scenery of the Urban Residence' represented in Korean films of the liberation period. It is assumed that public films reflect the human activities, residential culture and cityscape of those days. For the analysis, a pool of 7 Korean films from 1946 till 1949 was constructed. In these films, the sceneries of the urban life were represented as the following: 1) The western-style architectural spaces, such as cultural residence and apartment were emphasized to reflect the longing and curiosity of the general public for modern culture and lifestyle. 2) The cityscape including a narrow alley, crossroads and modern buildings was intentionally represented to express visually the city of Seoul under the slow wave of modernization.