• Journal of Korean Society of Forest Science
• /
• v.77 no.4
• /
• pp.421-428
• /
• 1988

The purpose of this study was to analyze the working time and the efficiency according to plot shape and plot size under the same conditions. We chose two stands which were relatively gently sloped end evenly distributed in number of trees and surveyed 198 plots, and 306 plots in each stand. 1. As to the time advantage of plot establishment method, the direct-four line establishment method was more favorable than the diagonal-line establishment method in a rectangular plot. 2. The method by Blumeleiss-$Me{\beta}$ trommel was more favorable than the method using a tape in a circular plot. 3. As to the time advantage, the circular plot was more favorable than the rectangular plot. Especially, the circular plot was twice more available than rectangular plot in small plot size, but enlargement of plot size gradually decreased time advantage of circular plot.

• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 1993.10a
• /
• pp.119-128
• /
• 1993

Effective machine capacity is affected by the physical and geometrical conditions of the fields. In the small and scattered farmland structure field efficiency is greatly influenced by plot geometry. In this paper, a method for estimating field efficiency and effective machine capacity was developed . The developed method was applied to Korean paddy cultivation. Various time elements related to farm operations for small and scattered plots are discussed in this paper . Available working time is divided into two parts, viz. the preparation time for machine operation and actual working time. Two kinds of machine efficiencies, namely , Machine Efficiency 1, applicable on a single large plot or set of well consolidated plots ; and Machine Efficiency 2, applicable on small and scattered multiple plots, are considered. Based assumptions made and steps followed to construct the model are discussed. Effective capacity of each machine based on different plot geometries are calculated y the model. Machine efficiency on a single plot increases with increase in the dimension of longer side of the plot . Low speed, low theoretical capacity machines have higher machine efficiency which is only slightly influenced by plot geometry. As plot geometry is improved , the machine efficiency of high speed, high capacity machines increases rapidly. The effects of short side length and plot size on machine efficiency on a single plot depend on the type of farm operation. For a particular plot shape, as plot size increases, machine efficiency on multiple plots increases rapidly. The effects of consolidation on machine efficiency is highly significant if the plot size is small and/or machine size is large.

• Journal of the Korean Society of Tobacco Science
• /
• v.4 no.1
• /
• pp.51-59
• /
• 1982

This experiment was conducted to investigate the effects of fertilization level, additional dressing time and form of nitrogen on the growth and formation of Alkaloid in flue-cured tobacco. The results are abstracted as follows. Length and width of harvested leaves, area of a leaf, leaf area per plant, number of harvested leaves, weight of a leaf, and leaf weight of a plant were larger in the $NO_3$-N plot than $NH_4$-N plot. Length, width and area of the middle leaves increased by additional dressing on 7 days before topping, but the dry weight Per unit leaf area of those was decreased. Leaf shape was broaden in additional dressing plots in comparison with 100% of basal dressing plot, but there is no difference among the additional dressing plots. And the smallest leaf shape index was shown at upper leaves in 100% of basal dressing Plot. Leaf weight of a Plaint was the highest in 12kg/10a Plot among $NO_3$-N form and in 12kg/10a plot among $NH_4$-N form. Total Alkaloid content was higher in $NH_4$-N plot between fertilization forms, and highest in 15kg/10a plot among fertilization levels and at the position of middle and upper leaves in the plot of 7 days before topping among additional dressing times.

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

• Proceedings of the Safety Management and Science Conference
• /
• 2009.11a
• /
• pp.649-657
• /
• 2009

The paper presents the measurement split split-plot models for saving the time and cost. The split split-plot designs developed are efficiently used to estimating the gauge R&R(Reproducibility & Repeatability) when the completely randomized design of all factors(such as high pressure and temperature) is expensive and time consuming. The models studied include three split split-plots considering the type of experimental units.

• The Korean Journal of Applied Statistics
• /
• v.26 no.5
• /
• pp.807-819
• /
• 2013

A recurrence plot can be used as a graphical exploratory data analysis tool before confirmatory time series analysis. With the recurrence plot, we can obtain the structural pattern of the time series and recognize the structural change points in a time series at a glance. Korean stock data shows the usefulness of the recurrence plot as a graphical exploratory data analysis tool for time series data.

• The Korean Journal of Ecology
• /
• v.9 no.1
• /
• pp.91-101
• /
• 1986

To investigate the distribution of Plantago asiatica Linne, almost, restricted on the road-side, the plant growth analyzed by experimental cultivation under the condition of tread-pressure; 10 times/day (7.33kg/$cm^2$ ), 20 times/day (12.27kg/$cm^2$), 30 times/day (20.05kg/$cm^2$ ) and the control plot (1.68kg/$cm^2$ ). The matter production in the 10-time-per-diem plot (7.33kg/$cm^2$ ) of tread-pressure howed more large value than that inthe control one (1.68kg/$cm^2$ ) and those in the 20-0time-per-diem plot (12.27kg/$cm^2$ ) and the 30-time-per-diem one (20.05kg/$cm^2$ ) small values than that of the control plot. Especially, the growth of roots and spikes was extremely repressed. The number of leaves, scapes and lateral buds tend to increase in the tread-pressure of 20 times/day (12.27kg/$cm^2$ ) and 30 times/day (20.05kg/$cm^2$ ). The water contents of roots along the increase of tread-pressure to continuosly decreased. By the increase of tread-pressure, T/R ratio and C/F ratio their group decreased. The plant growth (7.33kg/$cm^2$ ) in the 10-time-per-diem plot increased more than that in the control one is regarded as the effect of tread-pressure affection on the road-side distribution of this plant.

• Journal of the Korean Professional Engineers Association
• /
• v.1 no.1
• /
• pp.18-25
• /
• 1968

Higher yield in rice paddies is greatly dependent on adequately balanced and timely supply of water. A majority of rice paddy in Korea is generally irrigated by rainfall, but in many cases it has to be supplemented by artificial irrigation for optimum rice culture. Although the water requirement of rice plant is for higher Than that of athec crops, submerged condition of rice paddy is not Necessarily required. The moisture requirement of rice plant varies with its growing stages, and it is possible to increase the irrigation efficiency through reduction of water loss due to percolation in rice paddies. An experimental plots were set up by means of sandomized block design with three duplication; (a) All time submerged, (b) Economically controlled, and (c) Extremely controlled. Three different irrigation periods Were (a) Initial sage, (b) Inter-stage, and (c) Yast stage. The topsoil of the three plots were excavated to the depth of 30 cm and then compacted with clay of 6 cm thickness. There after, they were piled up with the excavated top soils, leveled and cored with clay of 6 cm thickness around footpath in order to prevent leakage. The results obtained from the experiments are as follows, 1. There is no difference among the three experiments plots in terms of physical and chemical conditions, soil properties, and other characteristics. 2. Culm length and ear length are not affected by different irrigation methods. 3. There is no difference in the mature rate and 1, 000 grain weight of rice for the three plots. 4. The control plot which was irrigated every three days shows an increased yield over the all the time submerged plot by 17.8 percent. 5. The clay lined plot whose water holding capacity was held 5 days long, needs only to be irrigated every 7 days. 6. The clay lined plot shows an increased yield over the untreated plot ; over all-the-time submerged plot by 18 percent ; extremely controlled plot by 18 percent, and economically controlled plot by 33 percent. 7. It may be saved in water requirement about one Thirds.

• Smart Structures and Systems
• /
• v.11 no.3
• /
• pp.299-314
• /
• 2013

This paper presents a nonlinear time series analysis technique for evaluating machine defect severity, based on the Recurrence Plot (RP) entropy. The RP entropy is calculated from the probability distribution of the diagonal line length in the recurrence plot, which graphically depicts a system's dynamics and provides a global picture of the autocorrelation in a time series over all available time-scales. Results of experimental studies conducted on a spindle-bearing test bed have demonstrated that, as the working condition of the bearing deteriorates due to the initiation and/or progression of structural damages, the frequency information contained in the vibration signal becomes increasingly complex, leading to the increase of the RP entropy. As a result, RP entropy can serve as an effective indicator for defect severity assessment of rolling bearings.

• Journal of Biomedical Engineering Research
• /
• v.39 no.2
• /
• pp.69-79
• /
• 2018

The present study proposes an algorithm that can discriminate between normal subjects and paroxysmal atrial fibrillation (PAF) patients, which is conducted using electrocardiogram (ECG) without PAF events. For this, time-domain features and random forest classifier are used. Time-domain features are obtained from Poincare plot, Lorenz plot of ${\delta}RR$ interval, and morphology analysis. Afterward, three features are selected in total through feature selection. PAF patients and normal subjects are classified using random forest. The classification result showed that sensitivity and specificity were 81.82% and 95.24% respectively, the positive predictive value and negative predictive value were 96.43% and 76.92% respectively, and accuracy was 87.04%. The proposed algorithm had an advantage in terms of the computation requirement compared to existing algorithm, so it has suggested applicability in the more efficient prediction of PAF.