• KOREAN JOURNAL OF CROP SCIENCE
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• v.14
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• pp.87-90
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• 1973

Optimum plot shape and size in a uniformity trial in the newly founded experimental farm of KAERI were determined for seed yield with the basic units consisted of 2.5m $\times$ 0.6m plot. Various plot sizes and shapes were made by combination of the basic units. Coefficients of variations for yield were 21% in local branch type variety Kumkang-Dairip and 20% in the introduced branchless type variety Clark. This result indicates that the field in the new experimental farm is appropriate for soybean yield trials when adequate number of replications are employed in the field experiment. In general, C. V. values were gradually decreased with increase of plot sizes. Although the data were not consistant, the errors for the long narrow plots tend to have somewhat smaller than for the square shape plots. A sharp decrease in C.V. value was found from the $4.5\textrm{m}^2$ plot in the variety Kumkang-Dairip and from the $6\textrm{m}^2$ plot in the variety Clark. These results imply that 5-$6\textrm{m}^2$ plot could be used for yield trials in early generations of hybrid progenies. 2.5-5m long plot with 3-4 replications will be practical for yield trials in the early hybrid generations. The C.V. values with 7.5m long plot was about 16% in both varieties and 15.3% in 10m plot. These results indicate that 7.5-10m plot with 3-4 replications could be employed in accurate yield test in the advanced generations.

• Journal of Forest and Environmental Science
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• v.15 no.1
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• pp.107-116
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• 1999

For the study on the variation of Pinus densiflora S. et Z. natural populations. 13 stands were selected in Kangwondo region in 1994. They were located in Hyoja-Dong, Chunchon-Si [plot 1]; Sinnam-Myun, lnje-Gun [plot 2]; Buk-Myun, lnje-Gun [plot 3]; Seo-Myun, Yangyang-Gun [plot 4 and 5]; Sonyang-Myun, Yangyang-Gun [plot 6]; Toseong-Myun, Goseong-Gun [plot 7]; Synrim-Myun, Wonju-Si [plot 8]; Dunnae-Myun, Hoengsong-Gun [plot 9]; Jinbu-Myun, Pyungchang-Gun [plot 10]; Sogumgang, Kangneung-Si [plot 11]; Seo-Myun, Ulchin-Gun [plot 12]; and Mitan- Myun, Pyungchang-Gun [plot 13]. The morphological characteristics of needles and cones were investigated for twenty individual trees from each population. The results are summarized as follows: 1. Among needle characteristics, length, the number of serration. and the number of stoma row were significantly different among populations and between individuals within a population. They were 69.3~91.9mm, 25.1~28.7 per 0.5cm, and 4.1~6.2 rows for abaxial side and 2.9~4.6 rows for adaxial side, respectively. 2. Among cone characters surveyed. length and diameter were significantly different among populations and between individuals within a population. They were 31.1~43.7mm and 20.0~24.1mm, respectively. 3. A highly positive correlation was observed between the number of stoma row of abaxial side and that of adaxial side. and between length and diameter of cone. But the number of serration was negatively correlated with all traits. 4. The distance from seashore was positively correlated with needle length and the number of serration, but negatively correlated with the number of stoma row and cone length. However, the altitude was positively correlated with the number of serration, but negatively correlated with the number of stoma row and cone length. 5. Cluster analysis using average linkage method for needle and cone characteristics showed two groups to Euclidean distance 1.0. They were group I consisting of plots 1, 8, 12, and 13 and group II of plots 2, 3, 4, 5, 6, 7, 9, 10, and 11. However, group II was divided again to Euclidean distance 0.8, that is a group including plots 2, 3, 9, and 11 and the other group comprising plots 4, 5, 6, 7, and 10.

• Journal of Biosystems Engineering
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• v.21 no.3
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• pp.343-356
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• 1996

The plot geometry of the paddy land is directly related to the performance of machines, especially those having a large size and high speed. The study was to investigate the optimum plot geometry from the standpoint of mechanization. A simulator, Field-Plot-Structure-Evaluation-System(FPSES) was developed for evaluation of the field performance of machines according to the plot geometry. The efficiency and capacity of different sizes of machinery used for rice farming functions were analyzed for a various combination of plot geometry, which could be used as reference for the land reclamation planning and mechanization programming. It is shown that the plot size of about two hectares having a length of 200m and width of loom may be optimum, considering the efficiency and capacity of large sized machinery available currently and in near future.

• Journal of the Korea Safety Management & Science
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• v.10 no.3
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• pp.245-251
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• 2008

The research proposes three ANOVA(Analysis of Variance) tests using expected mean square(EMS) algorithms in various split-plot designs. The variance tests consist of Never-Pool test, Sometimes-Pool test and Always-Pool test. This paper also presents two EMS algorithms such as standard method and easy method. These algorithms are useful to make a decision rule for pooling. Numerical examples are illustrated for various split-plot designs such as split-plot designs, split-split-plot designs, repetition split-plot designs, and nested designs. Pragmatically, the results are summarized and compared with popular ANOVA spreadsheets and data model equations.

• The Korean Journal of Applied Statistics
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• v.21 no.4
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• pp.695-704
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• 2008

The parallel coordinate plot is a graphical data analysis technique for plotting multivariate data. The parallel coordinate plot overcomes the visualization problem of the Cartesian coordinate system for dimensions greater than 4. But, using different ordering of coordinate axes in the parallel coordinate plot of the same data may make different interpretations. Hence, we can use the regular polyprism parallel coordinate plot as an alternative for overcoming the variable arrangement problem of the parallel coordinate plot.

• Journal of Sericultural and Entomological Science
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• v.9
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• pp.27-34
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• 1969

This study was conducted investigate the effect of Gibberellin and Urea on the growth of mulberry tree with the compound treatment, and the characteristic of silkworm when the mulberry leaves simply treated with GB and the compound treatment with GB and Urea were supplied. The results are as follows. 1. Mulberry tree A. The leaf weight per mulberry tree with the compound treatment of GB+ Urea was heavier in spring silkworm and the leaf yield was increased by 7% compared with the non-treatment plot. B. The growth of wattle, leaf length and leaf width was more accelerated in the compound treatment plot of GB+Urea, the single treatment plot of GB and Urea than th!: non-treatment plot in autumn silkworm, and there was observed an incredse yielding effect of 16% in GB+Urea plot, in 16% GB plot and 18% in Urea plot respectively as compared with th: non-treatment plot, hut yield per l000m unit of wattle length was the least in GB plot. C. In the composition of mulberry leaves of treatment, water and crude protein was increased in the compound treatment plot of GB + Urea and the single treatment plot of GB and Urea than the non-treatment plot, but dry matter and carbohydrate were decredsed. 2. Characteristics of Larva in spring silkworm A. The mortality ratio of 4 and 5 instar plot was equally high in the compound treatment plot of GB+ Urea and the pupation ratio of 4 instar plot was lower than other treatment plot. B. Although there was no significant difference observed in the cocoon weight of 10.000 1st-day worms in both 4 and 5 instar plots between each treatment plot, the single treatment plot of GB showed somewhat great than other treatment plots. C. There was no significant difference observed in the cocoon layer ratio between each treatment plot, but 4 instar plots was slightly higher than 5 instar plots. 3. Characteristics of Larva in Autumn silkworm A. The mortality ratio of the compound treatment plot of GB+ Urea and GB was higher than that of the nontreatment and single treatment plot of Urea. B. The pupation ratio of the single treatment plot of Urea was higher than that of the compound treatment plot of GB + Urea, and there was no significant difference observed between other treatment plot. C. The cocoon weight of 10.000 1st-day th instar worms was heavier in the single treatment plot of Urea than nontreatment plot, GB+Urea plot and GB plot. D. The cocoon layer ratio was no significant difference observed between each-treatment.

• Korean Journal of Agricultural Science
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• v.10 no.1
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• pp.9-21
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• 1983

The structures of oak stands were studied in relation to their productivity. Three plots classified by the site quality following to altitude, were selected on the oak stand located at Naryongri Eunsanmyun Buyeogun. The site qualities of the stand studied were generally estimated to be moderate in respect to some soil physical and chemical properties. Quercus variabilis was dominant species in the vegetation composition of the stand studied. The crown densities of the stand were varied from 65.4% in plot I to 78.2% in plot III and the parts, occupied with oak trees, ranged from 44.4% in plot I to 65.9% in plot III in the density. In the contrast to crown density, the growing stocks of oak trees ranged from $3.937m^3$ in plot I (73.4% of plot total) to $2.075m^3$ in plot III (84.3% of plot total). The occupied ratios, measured by crown class, exhibited dissimilarity between crown projection area and volume, and also the ratios brought into different patterns by plot. Highly significant correlations were proved between crown projection areas and volumes of individual oak trees by plot, but not proved in the relations by crown class. The cumulative growth, current annual increment and mean annual increment displayed various patterns by plot and by crown class in the heights, D. B. H. s and volumes of oak trees. The maximum values of current annual increment of height were generally recorded in 10 to 20 years, earlier than those of D. B. H. The mean annual increment of height, D. B. H. and volume maintained similar levels after about 10 years and fluctuated irregularly. The crown projection area and volume following to thinning decreased in the order of the thinning methods of grade A < grade B < crown thinning$90m^3/ha$ in about 40 years in the productivity of volume of the oak stand studied.

• Magazine of the Korean Society of Agricultural Engineers
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• v.20 no.2
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• pp.4695-4707
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• 1978

The objeative of this study is to study how to rapidly convert tidal land into cultivable land. The study of a rapid, reasonable desalinization method is conducted at Namyang tidal land which represents soil texture of tidal lands along the south west costa larea of Korea. Therefore, Researches were made at many Pilots in order to find a way of high efficiency of leaching with simpler facilities and cheaper costs. The results of study are briefly summarized as follaws: 1. Subdrainage efficieny is 35%. This is a Poorly drained area, and needs longer leaching desalinization period. 2. The efficieny of desalinization in P.V.C 16 meters plot is the same as that of mole drainage 2 meters plot. P.V.C 4 meters plot has desalinization effect as much as two times compared to P.V.C 16 meters plot. 3. Because the soil texture is silty-clay, desalinization in non-treated plot of sub-drainage and surface drainage desalinization take three times longer period in comparision with P.V.C 4 meters plot. 4. As to the desalinization rate of soluble salt in the soil, the efficieny of desalinization of the topsoil in P.V.C plots was 50% higher than that of mole drainage plot and about 170% higher than that of non-treated plot. In the deep soil salt accumulation at topsoil was observed in non-treated and mole drainage plots, but efficiency in P.V.C polt is about 40 times as high as that of mole drainage and non-treated plot. 5. As to the results of use gypsum and lime as sub-drainage soil improver, gypsum was 60% more efficieny than lime in the continuously inundated plot and 44% in the intermittently inundated plot. The efficieny of gypsum and lime in the intermittently flooded plot is 35% and 42% higher than that of continuously flooded plot reapeaticee1y.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.12 no.2
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• pp.29-39
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• 2009

Research was initiated to investigate a vegetation characteristics of the winter season by seeding periods. 3 seeding periods (Mid-December seeding plot, Late January seeding plot and Early March seeding plot) and 3 zones (the top zone, the middle zone and the bottom zone) in each plot were treated with 3 replications on the experimented slope. Data such as vegetation coverage (%), soil hardness (MPa), temperature ($^{\circ}C$) and moisture (%) content were analyzed. The vegetation coverage was high in Early March seeding plot, medium in Mid-December, and low in Late January seeding plot. Early March seeding plot was effective in moisture content, soil hardness, and temperature for the growth of vegetation when compared to Late January seeding plot and Mid-December seeding plot. From the standpoint of coverage ratio of plant species, the coverage of Dianthus sinensis and Albizzia julibrissin were high in the Late January seeding plot whereas the coverage of Lotus corniculatus and Cool-season turfgrass were high in Early March seeding plot. These results indicated that the high vegetation coverage of Dianthus sinensis and Albizzia julibrissin in Early March seeding plot was caused by scarification during winter season. There was no difference observed in plant height regardless of seeding periods except in early surveying time of May and June after seeding. As far as each zone of the plot was concerned, the vegetation coverage was high. in the bottom zone, medium in the middle zone and low in the top zone. The bottom area of the experimented slope was high in moisture content when compared to the middle zone and the top zone.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.11 no.3
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• pp.20-27
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• 2008

This study was conducted to investigate the influence of thinning and pruning on characteristics of forest stand, mesopore ratio and soil water content at the Pinus koraiensis stands in Gwangneung, Gyeonggido. The Pinus koraiensis had been planted in 1976 and thinning and pruning were carried out in 1996. A sample area survey was conducted at experimental plots (thinned and unthinned) in 1998 and 2005, and mesopore ratio and soil water content have been monitored from 2000 to present. Average tree height of the thinned plot increased from 10.9m to 13.2m and from 10.3m to 12.8m for the unthinned plot. Average D.B.H of the thinned plot increased from 15.9cm to 21.1cm and from 14.5cm to 16.7cm for the unthinned plot during the period 1998-2005. Crown density at the thinned plot increased from 81.5% to 95.0% and from 89.5% to 95.0% for the unthinned plot during the period 1998-2005. Mesopore ratio (pF2.7) of A layer soil at the thinned plot was 40.1% while that of the unthinned plot was 37.3%. Changes of mesopore ratio at unthinned plot were not associated with stand age, but those at thinned plot had increased and then decreased, showing declining of the practice effect. Average soil water content at the thinned plot were 23.7% and 22.4% for the unthinned plot. Soil watercontents at both plots have been increased with increase in stand age. But the difference of soil watercontent at each plot has been decreased, especially at the depth of 10cm.