• Coupled systems mechanics
• /
• v.2 no.3
• /
• pp.255-269
• /
• 2013

This paper targets to investigate the solution of fuzzy quadratic Riccati differential equations with various types of fuzzy environment using Homotopy Perturbation Method (HPM). Fuzzy convex normalized sets are used for the fuzzy parameter and variables. Obtained results are depicted in term of plots to show the efficiency of the proposed method.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2022.10a
• /
• pp.134-134
• /
• 2022

Mungbean is used for not only seed but sprout, so, consumption of mungbean has been on the rise in Korea. Life cycle of mungbean tends to be short among Legume. For that reason, Mungbean can be harvested for various cropping system and season per regions and farmers regardless of sowing date and harvesting date. So, Prior research is needed about growth characters and life cycle of mungbean per sowing period. Mungebean cultivar 'Dahyun' and 'Sanpo' supplied by Korea Agriculture Technology Promotion Agency(KOAT) is cultivated in wagner pot. Sowing period is proper time of seeding in Jeollanam-do and Gyeongsangnam-do that is major cultivation region of mungbean in korea from early May to mid July every 2 weeks. Length at maturity stage tends to increase from early May(sowing date: 4^th May) to early July(sowing date: 5^th July), but after that, It tends to decrease from mid July(sowing date: 19^th July). Number of branches and nods shows a similar trend. Length of pod has no tendency and no difference per sowing date. Number of pod per plants has also no tendency per sowing date. Test plots sowing in late May has the most number of pods.(Sanpo 22.9pods, Dahyun 16.8) Number of seeds per pod tends to increase to late May and Test plots sowing in mid July has the most number of seed per pod. In case of sowing at early May, Days of emergence is 7d. its summation of temperature is 132.2℃. After that, it tends to decrease to mid June. After mid June, Days of emergence is fixed to 3d. Average temperature growing up in this season, Summation of temperature from sowing to emergence takes the lowest point in test plots sowing in mid June.(Sanpo 88.6℃, Dahyun 88.6) Days of flowering tends to fasten from early May to mid July. Two cultivar shows same level. Days of maturity tends to fasten to mid June, after that tends to slow. In case that many research results about growth characters and life cycle mungbean per sowing period are drawn, it is expected that it result in increase of cultivation area and income of farmer.

• Korean Journal of Soil Science and Fertilizer
• /
• v.39 no.5
• /
• pp.292-297
• /
• 2006

A research was carried out to investigate the release pattern of slow release nitrogen fertilizer compound(SRNC) that is latex coated urea(LCU) and to recommend the application rate of the fertilizer at dry seeding rice culture in Honam plain area. The experiment was conducted at experimental field(Jeonbug series, fine silty, mixed, nonacid, mesic family of Fluvaquentic Endoaquepts) of National Honam Agricultural Research Institute. A medium late maturing rice variety (Dongjinbyeo) was seeded at the rate of $60kg\;ha^{-1}$ by drill seeder on April 1, 1997 and March 30, 1998. Fertilizer application rate was $160-90-110kg\;ha^{-1}$ for $N-P_2O_5-K_2O$. Soil ammonium nitrate($NH_4-N$) contents remained higher in all SRNC plots than conventional ones and higher with the increase of SRNC application rate until panicle formation stage, but the contents was higher in the conventional than NRNC plots at the heading stage. The plant hight was taller in SRNC than conventional plots until maximum tiller stage, but became similar in both conventional and SRNC plots at heading stage. The culm and panicle number was greater in SRNC than conventional plots throughout all growth stage, but the effective tiller rate was higher in conventional ones. Nitrogen efficiency was higher in the SRNC than conventional plots, but the efficiency was decreasing with the higher SRNC level. The spikelet number per unit area was greater in SRNC than conventional plots, and increased with higher SRNC level. The more spikelet number with higher NRNC level resulted in lower 1,000-grain weight. The rice yield in conventional plot was similar with only 60% SRNC level, but lower than 80% and 100% SRNC levels. However, slight lodging was observed in 100% SRNC level. In conclusions, we recommend NRNC application level as 80% of standard nitrogen application for early dry seeding culture of rice Honam plain area.

• Journal of Korean Society of Forest Science
• /
• v.12 no.1
• /
• pp.45-54
• /
• 1971

Ecological studies on the effect of an accidental fire on the composition of the post-fire vegetation in relation to the productivity system were made at the burned site on Mt. Samak located at Duckduwon-Ri, Sumyun, Chun Sung-Kun, Kangwon-Do, the same plots used in the previous study carried out in 1967. The result are summarized as follows. 1. In the productivity system, the standing crop measured was as follows; Carex Lanceolata var. Nana, Miscanthus purpurscens etc. were contained in the herbs and their individual number was larger than that of the woody plants. (Table 1). In the woody plants, Quercus Acutissima was the most abundant, showing larger number of tree than Quercus dentata. The S.D.R. value of the family Poaceae was the highest among the herbs and in the test plots, it was 4 times larger in number than in the controlled plots. (Table 3, Fig. 4, 5). 2. In the unburned sities, 5 dominant species were selected and by calculating their S.D.R., it was shown that woody plants, S.D.R. is 4.43 while it is 11.52 with herbs. (Table 4, Fig. 6). 3. When making comparisons with the standing crop on the higher around, it was found that the test plots had 522.45 gm more than the controlled and 1470. 53gm more than those on lower ground. These results were considered to indicate that high temperature caused by fire resulted in the increase of germination rate of seeds as it was seen in the previous study and it further stimulate the growth of the perennial plants. (Table 6, 7) 4. In the number of species, the standing crop was increased in the order of Genus Miscanthus and Genus Carex. and in the woody plants Genus Lespedeza was increased in the standing crop. 5. It was found that in the rest plots, total summed height was greater by about 6000cm than that in the controlled plots. 6. In conclusion, the forest fire gave a great loss to tall trees and woody plants burning them together with unmatured seeds. In the succession of the 2nd year it was considered that the growth of the perennial plants had been stimulated on the barned sites.

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

• Asian Journal of Turfgrass Science
• /
• v.5 no.2
• /
• pp.95-114
• /
• 1991

This paper was designed to estimate the interaction of the first productivity, light conditions and to analyze the ecophysiological productivity, growth characteristics grown under various shading conditions in Zoysia japonica . The results summarized this experiment were as follows; 1.After transplanting the grass, increasing rate of leaf number and total leaf length was remarkahly high at the early growth stage in the control and the 30% shading plot. 2.The increasing rate of leaf area ratio (LA R) in all the experimental plot was remarkable high at the early growth stage after transplanting the grass. Especially, the control and 30% shading plot in compared with another plots, were remarkably high at rate of leaf area. 3.The length and the node number of rhizome in the control and 30% shading plot were also high and the difference was significantly large by the growth stage. 4.Chlorophyll content was very high at 36days after transplanting and then decreased. Increasing rate of shade resulted in its low content. The rate of chlorophyll a to b was decreased by in-creasing rate of shade. 5.The content of soluble sugar in the control and 30% shading plot was low at the early growth after transplanting and high at the late growth stage. Its content in the plot of 70% shading was remarkably low throughout the growth stage. 6.The increasing rate of standing plant in all the experimental plots was high at the early growth stage after transplanting. Increasing rate of shade was typically low through all the growth stage.

• Journal of Korean Society of Forest Science
• /
• v.96 no.2
• /
• pp.151-159
• /
• 2007

This study was conducted to investigate the effects of thinning on changes in stand characteristics and understory vegetation in a silvopasture practiced Japanese larch plantation in the Research Forest of Kangwon National University, Korea. Three different thinning intensities (64%, 35%, and control) were applied. Before and after thinning, the understory plant species increased its number from 48 (7 tree species, 7 shrubs species, 28 herbaceous species, and 6 woody climbers) to 100 (11 tree species, 15 shrub species, 67 herbaceous species, and 7 woody climbers). Thinning made plants invade easily on the forest floor, and plot A (325 stems/ha) had much higher number of undersory species than those Of plot B (575 stems/ha) and control plot (1,150 stems/ha). In three years after thinning, understory aboveground biomass (kg/ha) of herbs were 523 for control, 1,230 for plot B, and 1,288 for plot A. The canopy coverage had remarkable influence on the understory biomass production, resulting in relatively small amount of herbage production on control plot. The differences were statistically significant between thinned plots and unthinned plot, but there were no significant differences among the thinned plots (p<0.05).

• Journal of Forest and Environmental Science
• /
• v.33 no.1
• /
• pp.22-32
• /
• 2017

An experiment was set to assess the effect of mixed plantings on initial growth and biomass yield of two common plantation tree species of Bangladesh namely Acacia auriculiformis (A) and Gmelina arborea (G). Study was carried out in the nursery bed of the Seed Research Laboratory and Nursery of Institute of Forestry and Environmental Sciences, Chittagong University (IFESCU), Bangladesh during February to November, 2015. The treatments consisted of two pure planting plots (100% A and 100% G) and five mixed planting plots (50%A: 50%G, 35%A: 65%G, 25%A: 75%G, 65%A: 35%G and 75%A: 25%G) of these two species. In nursery, seedlings were raised in a randomized blocks with four replicates of seven treatment plots. Periodic increments on height (cm), collar diameter (cm) and leaf/phyllode number of the seedlings was taken in every month and continued up to 10 months. The growth and biomass yield of seedlings were measured 10 months after the first seed was emerged. The effects of mixed plantation on growth and biomass were compared to that of seedlings grown in pure plantation. At the age of 10 months it was found that G. arborea seedlings were significantly tallest (240.13 cm) when planted with A. auriculiformis in a proportion of 25%A: 75%G, whereas A. auriculiformis were tallest in the pure 100% A plot, with an average mean height of 135.36 cm. Maximum collar diameter (1.38 cm) was recorded for G. arborea in the mixed plots 75%A: 25%G. Fresh and dry weight of shoots and roots of the seedlings were found significantly (p<0.05) highest in 50%A: 50%G plot for G. arborea. G. arborea also showed highest quality index when mixed with A. auriculiformis in a proportion of 50:50, with an average value of 8.96. The results revealed a positive correlation between seedling growth and various planting patterns.

• Journal of Plant Biology
• /
• v.17 no.4
• /
• pp.158-162
• /
• 1974

Some ecological attributes of perennial plants and Pb contamination were analyzed for study plots near an entrance of Nevade Test Site at Mercury Valley, Nye County, Nevada. The surface of the desert pavement soil was composed of stones (1 to 4cm diameter). The underside of each stone was coated with coarse and fine sand (about 90%). The profiles of soil were constituted with the A-horizon and C-horizon only. The soil pH at the plots ranges from 7.6 to 8.5, C/N was 13 and cation exchange capacity showed 15me/100g. Nine species and 42 number of individuals were found in all plots. Franseria dumosa and Larrea divaricata were dominant species. The discrete clumps of vegetation were consisted of 9 species of common perennials and these were covered about 25% on desert pavement, on the other words, bare area without vegetation was about 75%. The size and spacing of the plants was irregular. Community coefficient as comparison between shrub species in these study area and those in near the low elevation desert indicated a low degree of similarity. Density, cover and productivity in the study plots as compared with those in the nearest study areas in Mercury Valley showed a higher value. The soils in the studied area involved high heavy metal contents in the plant tissue was higher than those of its soil. The leavds of Lycium andersonii tended to accumulate more Zn and Mo than those of the other species. Larrea divaricata leaves accumulated very high leaves of Fe and Ephedra nevadensis were generally high in Mn. Lead contamination was apparent in foliage of desert vegetation collected alongside the roadway, reflecting the variation in traffic volume. Lead contents greater than fifteen-fold of normal (low traffic) were found in plant foliage alongside the heavily traveled roadway. Lead content of old foliage by the heavily traveled roadway was as much as 129 ppm but that of new foliage 17 ppm only.

• Korean Journal of Plant Resources
• /
• v.10 no.1
• /
• pp.11-16
• /
• 1997

Effects of calcium on the total tuber yield, dry matter content, internal brown spot and hollow heart of a processing potato cv. Atlantic were investigated to obtain some basic informations in summer cropping. The occurrence rate of the internal brown spots in cv. Atlantic tubers were highly decreased with the significant differences in the Ca-treated plots compared to the Ca-nontreated plots. However, no significant differences amongs Ca-treated plots were shown. Plant height and the number of main stems were not affected by the changes of the calcium levels, but top fresh weight was the highest in the plots of Ca(200kg/ha) level. In addition to its total yield, dry matter content, hollow heart was not affected by calcium fertilization. Therefore, the causal factor of the internal brown spot is attributed to the calcium deficiency in the tubers of cv. Atlantic.