• Journal of Life Science
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• v.16 no.2 s.75
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• pp.339-344
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• 2006

The aim of this study was to examine the timing and magnitude of growth spurt in skinfold, body musle and bone related variables aligned on peak height velocity in boys and girls. In the study design, the subjects and the method were used by the cross-sectional investigation. The subjects participated in this study were 7 through 18 years of age belonged to typical primary, junior, senior high school students, and about 250 males and 250 females in each age group. The total subjects were 2,798 males and 2,762 females. All subjects of this study were lived in Pusan metropolitan city, Korea. The growth velocity magnitudes of sum of the four sites sknfold thickness, body musle and bone related variables. Velocity curve chart of physique was the smoothed according to an approximation of splines by the Sigma Plot-2001 graphic program. In this study, age at PHV of girls occurred eariler about 2 years than boys. In sum of four sites skinfold thickness, PV occurred -2 years from PHV in boys, and PV occurred +2 years from PHV in girls, respectively. In humerus breadth, two PV occurred before and after PHV in boys, whereas PV occurred -1 year from PHV in girls, respectively. In femur breadth, PFV and PHV appeared to occure the same time in boys, PV occurred -2 years from PHV in girls, respectively, In arm circumference, PV occurred after PHV in both sexes. In calf circumference, PV occurred +2 years from PHV in boys, PCCV and PHV appeared to occure the same time in girls, respectively. In magnitudes of peak velocity of body height, humerus breadth, femur breadth, arm circumference and calf circumfence, boys obtained higher than girls, on the other hand, girls obtained higher than boys in sum of four sites skinfold variable. we need to longitudinal and scientific investigation by Korean government level in adolescent growth spurt study, because childhood and adolescence achive higher positive physical education effect than the other ages.

• Korean Journal of Remote Sensing
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• v.36 no.2_1
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• pp.155-165
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• 2020

In this present study, the sensitivity of O₄ Air Mass Factor (AMF) to Aerosol Peak Height (APH) has been investigated using radiative transfer model according to various parameters(wavelength (340 nm and 477 nm), aerosol type (smoke, dust, sulfate), aerosol optical depth (AOD), surface reflectance, solar zenith angle, and viewing zenith angle). In general, it was found that O₄ AMF at 477 nm is more sensitive to APH than that at 340 nm and is stably retrieved with low spectral fitting error in Differential Optical Absorption Spectroscopy (DOAS) analysis. In high AOD condition, sensitivity of O₄ AMF on APH tends to increase. O₄ AMF at 340 nm decreased with increasing solar zenith angle. This dependency isthought to be induced by the decrease in length of the light path where O₄ absorption occurs due to the shielding effect caused by Rayleigh and Mie scattering at high solar zenith angles above 40°. At 477 nm, as the solar zenith angle increased, multiple scattering caused by Rayleigh and Mie scattering partly leads to the increase of O₄ AMF in nonlinear function. Based on synthetic radiance, APHs have been retrieved using O₄ AMF. Additionally, the effect of AOD uncertainty on APH retrieval error has been investigated. Among three aerosol types, APH retrieval for sulfate type is found to have the largest APH retrieval error due to uncertainty of AOD. In the case of dust aerosol, it was found that the influence of AOD uncertainty is negligible. It indicates that aerosol types affect APH retrieval error since absorption scattering characteristics of each aerosol type are various.

• The Korean Journal of Physiology
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• v.5 no.2
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• pp.15-27
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• 1971

Physiological analysis of the physical exercise was made on 9 subjects performing mountain climbing. The course between two points (256 and 516 meters altitude) was 1,300 meters in distance and difference of vertical height was 260 meters making the mean grade of 20%. In the field, the heart rates during uphill or downhill walk were recorded by EKG radio-telemetry. In the laboratory, oxygen consumption was obtained by the recorded heart rates, using individual heart rate vs oxygen consumption diagram obtained by treadmill test. the following results were obtained. 1. Uphill walk time was 36.5 minutes, and during this period the mean heart rate was 149.0 heats/min and peak heart rate was 169.2 beats/min. The total heart beats during the uphill walk was 5.433 beats. 2. The ratio of individual mean heart rate during the uphill walk to the maximal heart rate distributed between 66.6% and 98.3%, and the mean of the total group was 83.1%. The ratio of peak heart rate of uphill walk to the maximal heart rate was 94.5% in the group. Thus uphill walk of a 20% grade mountain course was an exhaustive exercise. 3. Oxygen consumption during uphill walk was 2.22 l/min (ranged between 1.79 and 2.70 l/min) and the ratio of this to the resting oxygen consumption was 8.31. The peak value of oxygen consumption during uphill walk was 2.73 l/min and the ratio of this to the resting oxygen consumption was 10.39. 4. Energy expenditure during uphill walk showed a mean of 11.1 kcal/min and the peak expenditure rate was 13.6 kcal/min. The total energy expenditure during 36.5 minutes of uphill walk was 396 kcal. 5. In downhill walk, the time was 31.7 minutes, mean heart rate was 118.4 (ranged between 100.1 and 142.7) beats/min, and the peak heart rate was only 129.4 beats/min. The ratio of mean heart rate to the maximal heart rate was 66.3%. Total heart beats during downhill walk was 3,710 beats. The ratio of downhill oxygen consumption to the resting consumption was 5.70. The rate of energy expenditure was 7.5 kcal/min, and the total onery expenditure during the 31.7 minutes of downhill walk was 228 kcal. 6. The effect of training was manifest in the uphill walk and not in the downhill walk. After training in mountain course walk, i) the uphill time was shortened, ii) mean heart rate increased, iii) time vs heart rate curve became smooth and showed less frequent zig-zag, i.e., the depth of trough on the curve decreased and the magnitude was less than 10 beats. In non-trained subject the depth of trough on the curve was greater than 50 beats and appeared more frequently. 7. Mountain climbing is a good health promotion exercise. For the promotion of health the reasonable amount of uphill mountain walk exercise in a 20% grade course is a walk for 40 or 50 minutes duration once a week.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.27 no.4
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• pp.293-302
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• 1991

The anomalous sea level deviation or storm surge caused by the typhoon Thelma in 1987 are studied analysing tidal observation data at 7 stations in the south coast of Korean peninsula. The surges are calculated by subtracting the predicted tidal height from the observed tidal record. The tidal deviation at these stations along the coast are discussed in association with meteorological data. The sea level anomalies are studied by means of the empirical orthogonal function (EOF) analysis and the fast fourier transform (FFT) method. The results of analysis suggest that the peak value of surges are higher at the tidal stations in semi-enclosed bay and in long narrow channel than at the ones facing with the open sea. From the result of EOF analysis, the temporal and spatial fluctuations of storm surge can be described by the first EOF mode, which explains 63% of the total variances during the passage of typhoon Thelma. The deviation of storm surge in the studied areas indicates bi-modal peak during the passage of typhoon Thelma. From the results of FFT spectrum analysis, the peak of energy of autospectrum for surge, atmospheric pressure, and wind stress appeared at low frequency fluctuations band of 0.008-0.076 cph over the 4 stations. Auto-correlation function of surge showed periodicity, while that of atmospheric pressure and wind stress indicates no periodicity. The result of FFT analysis shows that the typhoon surges are related chiefly with the change of atmospheric pressure in an open bay (Cheju Harbor), but with the wind stress in a semi-enclosed bay (Yeosu Harbor).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.4 no.3_4
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• pp.92-98
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• 1971

With Saxidomus Purpuratus which were sampled near Yungdo, in the harbor of Pusan during the period from September 1967 to October 1968, the author investigated the maturity against seasonal change of water temperature; and shell length, height and width against live weight, respectively, and the reciprocal correlations of shell length, height and width, as well. The maturity, concerned deeply with tile developing procedure of gonad, is dependent on the change in water temperature. The value of maturity becomes higher from March to May, but in August with high temperature the value decreases temporarily. During the main spawning season from the late August to the middle of October, the value shows the peak throughout a year. After the period, it has decreased until January when the water temperature is below $10^{\circ}C$ The equations of shell length against live weight for male($W=0.4749L^{2.62307}$)and for female ($W=0.3438L^{2.77993}$) shell height against live weight ($W=0.3221L^{3.06661}$), and shell width against live weight ($W=3.5868L^{2.46646}$), show non-straight lines respectively. On the other hand, th: equations of shell length against shell height Y=0.818x+0.292 (r=0.958), shell length against shell width Y=0.520x+0.200 (r=0.799) and shell height against shell width Y=0.499x+0.516 (r=0.773) show straight lines, respectively.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.3
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• pp.115-121
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• 2021

Human's landing strategies have been explained through lower extremity kinetics in various conditions. However, how lower extremity kinetics respond when the two conditions between a load and landing height are combined is not yet understood. To achieve the purpose of this study, a total of 20 men and women were subjected to drop landing according to a load(No load, 10%, 20%, 30% of the body weight) at various landing heights(0.3 m, 0.4 m, 0.5 m). As a result of the study, the main effect of a load was not statistically significant in all variables. But increasing of the landing heights showed more flexion angle which was statistically significant in knee joint. In addition, as the landing height increased, the medial-lateral, anterior-posterior, vertical force, and loading rate increased, while time to peak vertical force decreased which was statistically significant. Thus, humans can successfully perform the landing motion even if the load is changed at various heights. However, it reacted more sensitively to the change in landing height than that load condition. The landing height can be prepared for recognition and shock absorption through visual information, but the weight level is difficult for the body to perceive and explains why it is more difficult to apply it to the landing strategy mechanism for shock absorption.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.1B
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• pp.83-90
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• 2009

This study describes the characteristics of distribution of lift-force acting under pier deck through physical experiment. The shape of peak wave pressure was sharp when compressed air existed but was not sharp without that. Values of lift-force was different between edge point and center point in the same block. Distribution of lift-force was expressed differently owing to dimensionless of deck length (l/L), wave steepness (H/L), clearance height per wave height (D/H). The dimensionless factor of D/H affected on the lift-force the clearance between still water surface and decks. This decided the maximum of lift-force. In the case of the same values of D/H, the lift-force are changed by the wave steepness (H/L). Because (D/H) become smaller as the wave steepness (H/L) is increased the height of decks must be decided with the condition which don't have the clearance with $D_{max}$ for the stable design of deck of pier. Effect of reducing lift force was greater in the on-shore than the off-shore according to compressed air existence. This researches points out that design of deck should retain compressed air in order to reduce wave lift force.

• Proceedings of the KIEE Conference
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• 1999.07d
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• pp.1624-1626
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• 1999

PD in defect of solid insulation system is very harmful since It often leads to deterioration of insulation by the combined action of the discharge ions bombarding the surface and the action of chemical compounds that are formed by the discharge. PD can indicate incipient failure, so it has been used to determine degradation of insulation. In this paper. we investigated PD in defects of solid insulation by using statical method and classified PD patterns with surface discharge, electrical tree and void discharge by using Kohonen network. we used peak charge, average discharge power, average discharge current, repetition rate, skewness, kurtosis, QN of the max pulse height vs. repetition rate $H_q(n)$ for analysis and classification.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 1996.11a
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• pp.24-29
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• 1996

The objective of this research is to study on the formations of thermal stratification in a room in case of several furniture fires such as trashcan, chair, carpet, sofa, mattress and wardrobe as a fire starter in a residential room by performing the experimental studies. The uniformly distributed fire in case of carpet showed that the ignition and the initial growth period were relatively short while the fully developed period was considerably long. The concentrated fires such as the mattress and wardrobe showed that the ignitions and the initial growth periods were relatively long. When fire spread to only one direction, like the case for the trashcan with a regular shape, there was one peak of temperature profile, and for the irregular shaped furniture such as chair, sofa, mattress and wardrobe, there were two or more peaks. The interface heights for the furniture fires were around 1(m) mataining constant state. However, at the time of the maximum temperature, the interface height was lowered to 0.25(m)-0.75(m) from the floor

• Korean Journal of Applied Biomechanics
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• v.14 no.3
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• pp.301-311
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• 2004

The purpose of this study was to verify the usefulness of the Mathcad program as a tool for the studying and teaching the sport biomechanics. A projectile motion was analyzed because it is the one of the most popular motion in sports activities. A 3 dimensional CG data for the high jump bar clear phase was used to calculate the initial velocity vector of the CG. Linear regression function and other functions such as cubic spline and derivative of Mathcad were used to calculate this vector. Finally, the approach angle to the bar and peak jump height was calculated. Programming in Mathcad was relatively easy compare to traditional computer language such as Fortran and C, because of the unique documentation method of Mathcad. Additionally the 2 and 3 dimensional graph function was very easy and useful to describe the mechanical data. If the use of Mathcad program is more popular in the field of sport biomechanics, it could greatly contribute to overcome the limit of research caused by the lack of proper programming ability.