• Korean Journal of Soil Science and Fertilizer
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• v.34 no.6
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• pp.407-412
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• 2001

This study was conducted to find out the effect of slow-release nitrogen fertilizer, such as latex coated urea(LCU) and Meister10(MS10) on direct seeded rice in dry soil(DS). Junghwabyeo, and early maturity rice cultivar was grown on the plots which were treated with None-nitrogen. urea. LCU and MS10 plot. Growth characteristic, yield and yield components were investigated. Nitrogen uptake-efficiency and physico-chemical properties of soil before-after experiment were analyzed. Plant height and number of tillers $m^{-2}$ in LCU and MS10 plot at early grow stages were higher than those in urea plot. Plant height and number of tillers $m^{-2}$ grown on the plot of Ms10 plot were higher than those of LCU plot. The number of seedling $m^{-2}$ were no significant differences among None-N, urea, and MS10 plot in DS. Heading date and leaf color were higher with Urea than LCU and MS10 plot. Culm length in LCU and MS10 plot were longer compared with urea plot, but panicle length was similar among with Urea, LCU and MS10 plot. Number of panicles $m^{-2}$ was greater in order of MS10 > LCU > Urea plot. Yield were greater in order of MS10 > LCU > Urea plot. Nitrogen uptake and nitrogen efficiency were greater in order of MS10 > LCU > urea plot. After the experiment, total content of nitrogen in soil was not changed at all treatments, but pH, P and Si of soil were lower than those of before experiment at all treatments.

• Journal of Korean Society of Forest Science
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• v.4 no.1
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• pp.26-29
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• 1965

1. The purpose of this study was to find out the best sampling form and sampling unit in forest survey. 2. The value of small sampling unit was over estimated in comparison with that of large sampling unit. 3. The value of circular form was over estimated in comparison with that of the others. 4. The smallest unit for estimation in area sampling were as follows. a) 0.06 ha. in the rectangular plot. b) 0.08 ha. in the square plot. c) 0.10 ha. in the circular plot. 5. Conclusion was as follows. The best sampling unit was 0.06 hectoare in the rectangular plot, which was most economic above all and gave preferable result for in the forest survey.

• The Korean Journal of Applied Statistics
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• v.27 no.2
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• pp.227-237
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• 2014

We use the regression model with the indicator variables in the case that we use qualitative variables as some predictor variables in regression analysis. We use the ANCOVA(Analysis of Covariance) model when comparing the response variable among groups while statistically controlling for variation in the response variable caused by a variation in the covariate. DD-plot can be used as a graphical exploratory data analysis tool before the confirmatory data analysis. With the DD-plot, we can discriminate the difference of groups in the regression model with the indicator variables or the ANCOVA model at a glance. Making DD-plot does not demand the statistical model assumption about error terms in regression model. Several examples show the usefulness of DD-plots as a graphical exploratory data analysis tool for the regression analysis.

• Bulletin of the Korean Chemical Society
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• v.29 no.4
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• pp.767-771
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• 2008

Second-order rate constants have been measured spectrophotometrically for the Michael-type reaction of 1-(Xsubstituted phenyl)-2-propyn-1-ones (2a-f) with amines in $H_2O$ at 25.0 ${\pm}$ 0.1 ${^{\circ}C}$. A linear Brønsted-type plot is obtained with ${\beta}_{nuc}$ = 0.25 ${\pm}$ 0.02, a typical $\beta_{nuc}$ value for reactions which proceed through a stepwise mechanism with attack of amine on the electrophilic center being the rate-determining step. Secondary alicyclic amines are found to be more reactive than isobasic primary amines. The Hammett plot for the reactions of 2a-f with morpholine is not linear, i.e., the substrate with a strong electron-donating group (e.g., 4-MeO) exhibits a negative deviation from the Hammett plot. However, the Yukawa-Tsuno plot for the same reactions exhibits an excellent linear correlation with ρ = 0.62 and r = 0.82. Thus, it has been proposed that the nonlinear Hammett plot is not due to a change in the ra te-determining step but due to ground-state stabilization through resonance interactions.

• Korean Journal of Soil Science and Fertilizer
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• v.16 no.1
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• pp.36-41
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• 1983

These studies were carried out to investigate the effects of potassium salts on the changes of chemical properties in submerged soil. Rice plants were cultured in submerged soil using potassium salts. Obtained results were as follows. In the submerged soil cultured with rice plants the value of pH was higher in the potassium chloride plot than in the potassium sulfate plot. The leaching of cations such as calcium, magnesium, potassium and ammonium were higher in the potassium chloride plot than in the potassium sulfate plot. On the other hand, the leaching of phosphate ion was slightly higher in the potassium sulfate plot than in the potassium chloride plot. The leaching of iron was higher in the planted plot than in the non-planted plot, but that of silica was higher in the non-planted plot than in the planted plot. However, the leaching of iron and silica was not affected by potassium salts.

• The Korean Journal of Ecology
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• v.23 no.6
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• pp.423-429
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• 2000

To understand the effects of elevated $CO_2$ concentration and temperature on seedling emergence of seven herbaceous species, the seedling emergence was monitored between November 1997 and May 1998 using a temperature gradient chamber and a $CO_2$-temperature gradient chamber. Experiment was conducted under current ambient condition (Control plot), 2$^{\circ}C$-warmed condition with ambient $CO_2$ (T2 Plot), 4$^{\circ}C$-warmed condition with ambient $CO_2$ (T4 plot). and 4$^{\circ}C$-warmed condition with 1.8 fold of ambient $CO_2$ (CT4 plot). Species tested in this study were Digitaria adscendens, Echinochloa crus-galli, Panicum bisulcatum, Setaria viridis. Oenothera biennis, Andropogon virginicus, and Imperata cylindrica. Each species often dominates in the herbaceous stage of secondary succession in Japan. The mean seedling emergence times for all species were significantly increased to 23.6 and 32.2 d in the T2 and T4 plot compared to the Control plot, respectively. The most sensitive and insensitive species in seedling emergence time in T2 plot were O. biennis and D. adscendens, respectivel.y, and those in the T4 and CT4 plot were I. cylindrica and D. adscendens, E. crus-galli and A. virginicus, respectively. All experimental species showed no significant difference in the seedling emergence rate between treatments except for O. biennis and I. cylindrica. O. biennis showed a great decrease in the seedling emergence rate from 83.3% in the Control plot to 38.0%, 14.7%, and 29.3% in the T2, T4, and CT4 plot, respectively. Elevated $CO_2$ had very little effect on the seedling emergence. From these observations, it is expected that increased temperature would greatly advance the vegetative recovery time after disturbance through the advancement of seedling emergence time.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.13 no.2
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• pp.72-79
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• 2010

This research was initiated to investigate the revegetation characteristics under seedling types of native woody plants on a disturbed slope. 4 different seedling types of woody plants (control, unit seedling plot, nature seedling plot, pot seedling plot) with the same woody plants (Rhus chinensis Mill, Albizzia julibrissin Duraz., Quercus acutissima Carr., Pinus densiflora S. et Z.) were treated with 3 replications on the experimental disturbed slope. Data such as the died number of native woody plants, growth height and visual quality were analyzed. The died number of plants were high in unit seedling plot when compared to the rest plots of seedling types. From the standpoint of died plant species, the died number were high in Rhus chinensis and Albizzia julibrissin whereas the died number were low in Quercus acutissima and Pinus densiflora. That's because we used 1-year old seedlings of Rhus chinensis and Albizzia julibrissin and 3-year old seedling Quercus acutissima and Pinus densiflora. This result indicated that the died reason of native woody seedling was not species but seedling age. Both growth height and visual quality were ranked first in the pot seedling plot, second in the nature seedling plot, third in the unit seedling plot, and last in the control plot, respectively. However, the difference of both growth height and visual quality in each seedling plot was not observed on the 11 months after planting. Especially, the main reason of low rooting and growth value in the unit seedling plot was due to wooven fabric outer crust of pot that obstruct seedling rooting into the soil. We concluded that pot seedling of native woody plants was effective in the viewpoint of the ecological disturbed slope revegetation.

• Journal of Korean Society of Forest Science
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• v.3 no.1
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• pp.23-27
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• 1963

A research was made through a experimental cultivation during a period of 7 years (1956~1962) to determine the yearly yield, the total gross yield over 7 year's period and the maximum availability of stock timbers used as the germination bed of cortinellus edodes (Berk) Ido et Imai. The results are summarized as follows : (1) Research and plot scheme: Two experimental plots were established-plot "A" in the experimental forest of this college; plot "B" in the campus woods, 400 timber beds were furnished in each. The kinds of timbers used are : Quercus Serrata Thumb 140. Quercus acutissima Carr. 140, Quercus crispula BI 120. The environmental condition in plot "A" was better then that in plot "B" and the former showed greater yield than the latter. (2) yield : In plot "A" the total yield was 58.875kg and some of the timbers was still continuing germ in this seven after closing of the plot. In plot "B" the total yield was 56.90kg and after the sixth year no more germination was observed. In conclusion, plot "A" showed greater yield and longer germination than plot "B". (3) Germination efficacy and the kinds of timber: The best result was abserved on Quercus serrata, thumb Quercur acutissima Carr, stood next and then came Quercus crispula BI. Betula platyphylla was tried, but the result was worst. (4) Availability limits of timber beds: Quercus serrata Thumb with diameter 12~15cm had the longest availability more than (6~7 years) and Quercus acutissima Carr with diameter 12~15cm showed 6~7 year's availability. The shortest availability was found in Quercus crispula with diameter 6~9cm. Any kinds of timber with diameter 6~9cm had only 4~5 years of availability (5) In the table showing the yearly germination quantity, the figure of December and Jaunary of the 4th and 5th year shows the yield obtained in the semi-cellar paper house. This tells that there is good promise of winter cultivation of cortinellus edodes (Berk) Ido et Imai on matured timber beds.

• Journal of the Korean Wood Science and Technology
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• v.36 no.3
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• pp.55-60
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• 2008

This study was carried out to investigate the effect of charcoal meal application on the quality of the wood. As the results, it was observed that annual ring width of seedlings was wider in the plots treated with charcoal meal than the control plots. Depending on the kind of charcoal, annual ring width was widest in the plot treated with Larix kaempferi charcoal, and then was observed in order of Pinus koraiensis > particle board > Quercus acutissima. Latewood percentage and specific gravity were lower in the plots treated with charcoal than the control plots and lowest in Larix kaempferi charcoal plot among the plots treated with charcoal. Tracheid length was longer in the plot treated with powder charcoal than the control plot but tracheid width was not significantly different from the control plot. The cell wall thickness of earlywood was not significantly different between the plot treated with charcoal and the control plot but that of latewood was thicker in the plots treated with charcoal than the control. Microfibril angle was smaller in the plot treated with granulated charcoal than the control plot. However, there was no significant difference between the plot treated with powder charcoal and granulated charcoal.

• Communications for Statistical Applications and Methods
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• v.10 no.2
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• pp.371-385
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• 2003

In this paper, contour plot is considered as a method to explore the structure of categorical data. For this purpose, the paper suggests a method to sort two-way contingency table with respect to the expected marginals. It is found that the suggested plot provides us with valuable information for the underlying data structure. Firstly, we can investigate independency between the categories by examining the differences of expected frequency contours and observed frequency contours. With the plot, we can also visually investigate the existence of outliers inherent in the data. These properties of the suggested contour plot will be demonstrated by several sets of real data.