• Journal of Preventive Medicine and Public Health
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• v.9 no.1
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• pp.25-29
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• 1976

A study was conducted on 2,210 officials in Jeonbug Province to check out their physical growth, development and nutritional state during the period June 1st 1975 to August 31, 1915. As the results of this study, the following conclusions were reached: 1. Physical measurement a. Body height: The mean body height of male was $166.8{\pm}4.6cm$ and that of female was $156.3{\pm}4.9cm$. The highest value of mean body height was $167.1{\pm}3.9cm$, showing by male of administrative job. The lowest valthe of that was $165.7{\pm}5.2cm$, showing by the male functional job, while the difference of body height was not significant in female. b. Body weight: The mean body weight of male was $61.5{\pm}4.6kg$ and that of female was $51.2{\pm}3.9kg$. The administrative job heavier than functional job of male by type of job, while that of female of functional job heavier than administrative job. c. Chest-girth: The mean chest-girth of male was $90.8{\pm}3.2cm$ and that of female was $83.6{\pm}3.6cm$. 2. Physical growth and developmental state a. The relative body weight was normal in male except the young man under 25 years, while that of female was under the level of standard. b. The relative chest-girth was showed standard values by all age group of officals. c. The Rohrer and Kaup indices were showed standard values except under 19 years officials and 30 to 34 years female officials. 3. Vervaeck index for nutritional status was appeared normal in male but under the values of standard in female.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.30 no.3
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• pp.123-133
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• 2018

We studied the change process in the design parameters (conditions) of structural sections of vertical/slope breakwaters in Korea over the long term based on an analytical review of the latest design recommendations. This study found the following. 1) Design wave heights have increased gradually with the increase in the wave height of deep sea waves. 2) The relative design wave height ($H_{1/3}/h$) changed from 0.5 in the 1970s to 0.6~0.7 today. This means that design wave heights are overestimated compared with the water depth. 3) Before 1999, the design water level was based on high water during an average spring tide, but this has been increased since 2000 because of additional consideration of anomalous sea levels. 4) Before 1999, the relative crest heights of the investigated breakwaters was 0.6~0.7, but after 1999 this increased to a mean of 1.0 and maximum of 1.26.

• Journal of Korea Foresty Energy
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• v.20 no.2
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• pp.58-68
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• 2001

This study was carried out to investigate the growth and biomass production of Abies koreana seedlings under different relative light intensity. The 5-year-old potted seedlings were grown for 24 months under different light intensity of 100%, 50%, 30%, 10% and 2% of the natural full light intensity. The results were as follows: 1. Height growth was similar in the seedlings under different light intensities except in 2% of the full sun light intensity, having shown the lowest height growth. 2. Root collar diameter growth was reduced gradually by decreasing of the relative light intensity. 3. The seedlings which were grown under relatively low light intensity showed the later starting date of the stem growth in the next spring and showed the smaller number of new needles, and the smarter number and the shorter length of new shoot of the seedlings. 4. Total dry mass including the dry mass of leaves, shoot and root was reduced by decreasing of the relative light intensity. 5. In case of the seedling grown in one year shading condition, the ratio of the dry mass of current-year needles and stem to that of the above one-year-old needles and stem was ranged from 0.99$\pm$0.25 to 1.06$\pm$0.06 and was not significally different among the seedlings grown under 100%, 50% and 30% of the relative light intensity. And the radio was ranged from 0.60$\pm$0.04 to 0.52$\pm$0.03 in the seedlings grown under 10% and 2% of the relative light intensity, respectively. In case of the seedling grown in two years shading, the ratio of the dry mass of current-year needles and stem to that of the above one-year-old needles and stem was ranged from 0.79$\pm$0.04 to 1.00$\pm$0.03 and was not significally different among the seedlings grown under 100, 50, 30% and 10% of the relative light intensity. And the ratio was 0.29$\pm$0.03 in the seedlings grown under 2% of the relative light intensity, respectively. 6. T/R ratio of the seedlings grown in one year shading condition was ranged from 3.35$\pm$0.33 to 4.61$\pm$0.25 and was not significantly different among the relative light intensities of 100%, 50%, 30% and 10%. The seedlings grown under 2% of relative light intensity showed the highest T/R ratio of 7.36$\pm$0.15. In case of the two years shadings the T/R ratio was ranged from 1.76$\pm$0.11 to 3.12$\pm$0.19 and increased as relative light intensity decreased except 2.01$\pm$0.14 in 2% of relative light intensity.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.43 no.2
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• pp.87-100
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• 2007

This study was carried out to offer fundamental data for improving the fishing efficiency of the Danish seine. The net height and the shape in the water was measured to analyze the efficiency of the existing Danish seine. And then, an improved fishing gear was developed based on the results and was tested in the field. Measuring devices were attached on center of a ground rope and a head rope. The net height is the spread distance between the ground rope and the head rope, which was measured on the different ratio of buoyancy. The results are obtained as follows. The net height estimated from the design plan of horizontal hanging ratio 0.40 in the existing Danish seine A and B estimated both 4.94m. The net height of the existing Danish seine A and B was respectively 1.8m and 2.3m, which form 36.4% and 46.2% of the net height estimated from the design plan. Buoyancy was changed as 79.5% and 96.2% relative to the sinking force in the existing Danish seine. The net height of 79.5% was 3.95m which increased to 80% of the estimated net height. The other shows the same result with the first case. It is not necessarily that the high buoyancy/sinking force ratio make the high net height, 80% is adequate as the buoyancy/sinking force ratio. In case of the improved Danish seine, the mean net height was about 5.0m, means 58.3% of estimated net height 8.58m.

• Journal of Environmental Science International
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• v.26 no.5
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• pp.585-590
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• 2017

The Diameter at Breast Height (DBH) provides information about the volume growth of a tree. In this study, we estimated the relative growth rates of Castanea crenata and Pinus rigida as 4.07% and 3.73%, respectively. Although the difference was low, we demonstrated that the growth rate of C. crenata is slightly faster than that of P. rigida. After calculating the relative growth rate for each section, we found that the relative growth of C. crenata decreased with time. However, the relative growth rate of P. rigida showed an overall increase. The gap widths of both species showed an increasing trend. However, the gradient of the two species was different. The gradient of C. crenata was approximately 12.0, but that of P. rigida was approximately 4.7. This means that the volume growth of C. crenata was faster than that of P. rigida during 4 years. However, this was relatively a short period for measuring the volume growth pattern, and we believe that additional useful information can be obtained by conducting long-term ecological monitoring. Results of canonical correspondence analysis showed that among the climate variables, temperature was significantly related to the gap widths for both species.

• Journal of the Korean GEO-environmental Society
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• v.4 no.3
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• pp.51-59
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• 2003

Loading tests were carried out for model geocell to study the reinforcing effect by variation of tensile strength, cell height, soil density and embedded depth of geocell. From the result, it could be seen that the ultimate bearing capacity of the geocell system was influenced rather by the connection strength than by the tensile strength of geocell material. Bearing capacity increased with the increase of height to width ratio of geocell for the same relative density, strength and embedded depth. And the bearing capacity ratio(BCR) was higher at low relative density of sand than that of high relative density. The increase of bearing capacity was higher at geocell with high tensile strength than that of low tensile strength. And the influence was clear at higher relative density. Also the BCR was higher at shallow embedded depth of geocell. Without consideration of tensile strength of material, the application of bearing capacity formula suggested by Koerner seems not suitable for the special case with low tensile strength of geocell material.

• Journal of The Korean Society of Grassland and Forage Science
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• v.8 no.1
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• pp.26-32
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• 1988

This study was conducted to determine the effects of cutting frequency and cutting height on agronomic characteristics and yield performance of sorghum-sudangrass hybrid, cv. Pioneer 855 F on the experimental field of Livestock Experiment Station, Suweon. The results are summarized as follows: 1. The relative contribution of leaf component to total yield was higher when the plants were cut frequently rather than when defoliated only a few times, and tend to be higher with high cutting. 2. Leaf Area Index (LAI) was the highest at the primary growth of two cutting times scheme and the first regrowth for three or four cutting times a year, but LAI, in general, was not related to cutting height. 3. Crop Growth Rate was the heighest at the first regrowth-plants grown in summer, and it was also related to the amount of stubble left at the previous cut. 4. Dead stubbles were not occurred when plants were cut before heading, but those were accompanied by the frequent and low cutting. 5. Total fresh fodder and dry matter yield were the highest at two times cut a year, and decreased with frequent cutting. The optimum cutting height at two times cut was ca. lOCm height stubble from the ground level, but yield increased with higher level cutting at the three or four times cut a year.

• Journal of Korean Society of Forest Science
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• v.99 no.2
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• pp.204-212
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• 2010

This study was performed in 22 unthinned Larix olgensis plantations in northeast China. Data were collected on 95 sample trees of different canopy positions and the diameter at breast height ($d_{1.3}$) ranged from 5.7 cm to 40.2 cm. The individual tree models for the prediction of vertical distribution of live crown, branch and needle biomass were built. Our study showed that the crown, branch and needle biomass distributions were most in the location of 60% crown length. These results were also parallel to previous crown studies. The cumulative relative biomass of live crown, branch and needle were fitted by the sigmoid shape curve and the fitting results were quite well. Meanwhile, we developed the crown ratio and width models. Tree height was the most important predictor for crown ratio model. A negative competition factor, ccf and bas which reflected the effect of suppression on a tree, reduced the crown ratio estimates. The height-diameter ratio was a significant predictor. The higher the height-diameter ratio, the higher crown ratio is. Diameter at breast height is the strongest predictor in crown width model. The models can be used for the planning of harvesting operations, for the selection of feasible harvesting methods, and for the estimation of nutrient removals of different harvesting practices.

• Journal of Korea Water Resources Association
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• v.46 no.5
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• pp.491-504
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• 2013

In this study, wave breakings over a shelf region are investigated under irregular wave conditions through laboratory experiments in a wave flume. Numerical simulations based on the Boussinesq-type equations are also conducted. The characteristics of breaking waves such as significant wave height, crest and trough heights, the mean water level and the stable wave height are obtained by analyzing laboratory measurements in detail. Obtained results are compared with those of the Boussinesq-type equations model. A very reasonable agreements is observed. The broken waves over a horizontal bottom asymptotically approach a stable wave height($H_{stable}$). In this study, the relative stable wave height is found as $H_{stable}/h{\fallingdotseq}0.56$ for irregular wave.

• Journal of Welding and Joining
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• v.16 no.3
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• pp.55-63
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• 1998

Among the position sensing methods available, the arc sensor which utilizes the electrical signal obtained from the welding arc itself is one of the most prevalently used methods, because it has an advantage that no particular sensing device is necessary and real-time sensing of a groove position is possible directly under the arc. The authors have already developed a seam tracking system that contains a new arc sensor algorithm, which uses the relative welding current variation according to the tip-to-workpiece distance in GMA welding. In this study a torch height control algorithm for automatic weld seam tracking was proposed for completing the previous system, which uses an on-off control technique. To implement the torch height control algorithm during weld seam tracking the system parameters which include 2nd averaging range, weighting factor for 2nd moving averaging, and Z-directional basic compensation distance were determined by experimental analysis. Finally the two different height control methods, one is simple on-off control and the other on-off control using a reference current value , were compared in their tracking abilities.