• Journal of the Korean Society of Environmental Restoration Technology
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• v.24 no.1
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• pp.97-110
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• 2021

Vegetation index information is an important figure that is used in many fields such as landscape architecture, urban planning, and environment. Vegetation may vary slightly in vegetation vitality depending on photosynthesis and chlorophyll content. In this study, a range of vegetation worth preserving in the Taehwa River water system was determined, and hyperspectral images of drones were acquired (August, October), and the results were presented through DVI(Normalized Defference Vegetation Index), EVI(Enhanced Vegetation Index), PRI(Photochemical Reflectance Index), ARI (Anthocyanin Reflectance Index) index analysis. In addition, field spectral data and VRS-GPS(Virtual Reference System-GPS) surveys were performed to ensure the quality and location accuracy of the spectral band. As a result of the analysis, NDVI and EVI showed low vegetation vitality in October, -0.165 and -0.085, respectively, and PRI and ARI increased to 0.011 and 7.588 in October, respectively. For general vegetation vitality, it was suggested that NDVI and EVI analysis were effectively performed, and PRI and ARI were thought to be effective in analyzing detailed characteristics of plants by spectral band. It is expected that it can be widely used for park design and landscape information modeling by using drone image information construction and vegetation information.

• Korean Journal of Environmental Biology
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• v.18 no.1
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• pp.21-31
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• 2000

We investigated seasonal variation of microalgal assemblages, sea water temperature, salinity and suspended solid and the parameters measured daily from January 1998 to October 1999 at a nearshore shallow-water in Marian Cove, Maxwell Bay, King George Island, the Antarctic. Annual mean surface water temperature was -0.3$0^{\circ}C$ and the highest water temperature was 4.53$^{\circ}C$ (22 January 1999) and the lowest water temperature was -2.07$^{\circ}C$ (23 August 1998). Annual mean salinity was 33.38 psu, ranging from 42.80 psu (6 January 1999) to 19.50 psu (6 June 1999). Annual mean suspended solid (SS) during two years was 34.14 mgㆍ1$^{-1}$, ranging from 60.62 mgㆍ1$^{-1}$(7 March 1998) to 12.90 mgㆍ1$^{-1}$ (26 December 1998). Chlorophyll $\alpha$ (Chl $\alpha$) concentrations were measured in order to know seasonal variations of microalgae in the surface seawater. Annual mean of total Chl a concentration was 0.55$\mu\textrm{g}$ㆍ1$^{-1}$, the highest Chl $\alpha$ concentration (12.16$\mu\textrm{g}$ㆍ1$^{-1}$) appeared in 4 October 1998, the lowest Chl $\alpha$ concentration appeared 0.19$\mu\textrm{g}$ㆍ1$^{-1}$, Monthly mean total Chl $\alpha$ concentration was high in October 1998 (1.32$\mu\textrm{g}$ㆍ1$^{-1}$) and low in July on 1998 (0.28$\mu\textrm{g}$ㆍ1$^{-1}$). Annual mean nano-sized Chl $\alpha$ concentration was 0.40$\mu\textrm{g}$ㆍ1$^{-1}$, monthly mean nano -sized Chl $\alpha$ concentration was high in November 1998 (0.90$\mu\textrm{g}$ㆍ1$^{-1}$), and low in July 1999 (0.22$\mu\textrm{g}$ㆍ1$^{-1}$). Annual mean micro-sized Chl $\alpha$ concentration was 0.15$\mu\textrm{g}$ㆍ1$^{-1}$ monthly mean micro-sized Chl $\alpha$ concentration was high in October 1998 (0.81$\mu\textrm{g}$ㆍ1$^{-1}$), and low July 1998, January, February and September 1999 (0.05$\mu\textrm{g}$ㆍ1$^{-1}$). More than 65% of total Chl $\alpha$ was concentrated during spring and summer time between October and March. Microalgal variation appeared to be due to physical factors of seawater in the Antarctic nearshore from 1998 to 1999. The reason why micro-sized Chl $\alpha$ did not increase during austral summer was the bay had been frozen by decrease of water temperature. We think that total microalgal abundance was decreased because the summer microalgal abundance was determined by variation of water temperature during winter season. [Chl $\alpha$ concentration, Microalgal assembalges, Seasonal variation, the Antarctic nearshore].

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.7
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• pp.214-221
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• 2018

The purpose of this study is to analyze the shipbuilding structure of field tangerine by ten days and by month. By estimating and analyzing the price flexibility function of field tangerines, this study determines whether the shipment control can stabilize and increase the income of field tangerine farmers and provides policy implication. Considering the overall market, a 1% increase in shipment volume indicates that the coefficient of price flexibility varies with ten days and month. The greatest decline is from late October to early January. Therefore, a greater necessity of shipment control is required during late October and early January. The coefficient of the dummy variable (DUM_Q) indicates the year in which the quality declines is statistically significant and sign. The coefficient of the dummy variable (DUM02) represents the year in which more than 7 days after the New Year holidays are in February is statistically significant and sign from early October to late January. Therefore, it can be seen that the necessity of shipment control is more required when New Year holidays are in February. The greatest decline in the coefficient of price flexibility is from October to December. Therefore, a greater necessity of shipment control is required during October and December. The signs of coefficients of DUM01 and DUM_Q dummy variable of the price flexibility function suggest that the need for shipment control is more important when quality is worse than better quality and that the necessity of shipment control is more required when New Year holidays are in February, respectively.

• Asian Journal of Turfgrass Science
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• v.26 no.1
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• pp.35-43
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• 2012

These studies were carried out to ascertain the effects of paraffin oil on prolongation of the green leaf color period in Zoysiagrass. Fifty-fold diluted 98% paraffin oil treatment obtained the lowest reduction rate of green color. In early October we sprayed 50-fold, 100-fold and 200-fold diluted 98% paraffin oil in a Zoysia japonica field in Hapcheon of Gyeongnam and Sangju of Gyeongbuk and in a Z. matrella field in Gumjung of Busan and Anseong of Gyeonggii. Leaf color maintained for 60 days after treatment in Zoysia japonica. Leaf color remained for 60 days after treatment in Anseong, Hapcheon and Sangju when treated in the mid-October. Chlorophyll content was higher in paraffin oil treatment areas than in control areas in early October. Weight reduction rate was lower in the paraffin oil treated than in untreated leaves of Zoysiagrass when sprayed in Gumjung and Anseong in early October and mid-October, respectively. The chlorophyll content in leaves of Z. japonica was increased by increasing the spray volume of paraffin oil in the same dose treated in Lexington, Kentucky, USA. Paraffin oil can be used to prolongate of Zoysiagrass leaf color.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.3
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• pp.253-261
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• 2012

We investigated the reproductive capacity of starry flounder Platichthys stellatus from the Uljin (UJ) marine ranching area and compared it to that of P. stellatus from the coastal waters of Pohang (PH). In UJ, female gonadosomatic index (GSI) peaked in October ($3.14{\pm}0.87$) and male GSI was high in October and December. In PH, female GSI peaked in January ($18.64{\pm}2.15$) while male GSI began to increase in October and remained high until March. Most ovaries of UJ females were immature with perinucleus oocytes, although the testes of UJ males were ripe in January. Both the ovaries and testes of PH starry flounders were ripe from January to March. The plasma estradiol-$17{\beta}$ ($E_2$) levels of UJ females were highest in October ($4.09{\pm}1.90$ ng/mL) although the testosterone (T) levels of UJ males were highest in December ($3.81{\pm}0.78$ ng/mL) and decreased gradually until April. The $17{\alpha}$,$20{\beta}$-dihydroxy-4-pregnen-3-one ($17{\alpha}20{\beta}P$) levels of UJ females were not detected. The E2 levels of PH females were highest in December ($36.25{\pm}33.07$ ng/mL) and $17{\alpha}20{\beta}P$ levels were highest in March ($5.51{\pm}0.95$5 ng/mL). The T levels of PH males were highest in December ($4.03{\pm}1.34$ ng/mL) and decreased gradually until October. Taken together, these results suggest that most females from UJ did not reach maturation with a spawning period that was considered to be between December and January.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.3
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• pp.211-215
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• 2002

This study was carried out to find out the optimum harvesting time on the basis of physiological characteristics, yield and commercial value in four years old ginseng. For this purpose, the changes of agronomic growth characteristics of the aerial and underground parts with different growing stages were examined with fourth year ginseng. The leaf growth was dramatically increased from the mid-April (shooting stage) to the mid-May (flowering stage), and the growth was nearly completed by the mid-May, but the stem growth continued by the mid-August. The weight of fresh root decreased from the April (20.7g) to the June (18.2g), but increased from the June to the October(45. 1g). The yield of fresh root per "Kan" was 1.5 kg, 1.2kg and 1.3kg at the April, the May and the June, respectively, thereafter continually increased to 2.9 kg of the October, which showing the maximum yield. In conclusion, the ginseng root was generally harvested from the September to the October at farm-house, but it had better be harvested after the mid-October rather than from September to October considering the weight of dry root and the yield of fresh ginseng.h ginseng.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.3
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• pp.317-322
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• 1987

In order to find out the optimum transplanting date of mat rush, this study was investigated ecological characters, yield components and yield of three varieties (Okayama#2, Sajanami and Sedo #4) at 5 transplanting dates(October 25, November 5, November 15, November 25 and March 5). As transplanting date was delayed, the flowering date and maturing date was delayed also and stem length was longest in October 25 transplanting but it grew short in the late transplanting. Number of stems per plant was increased most in October 25 transplanting, that is, increased to 143 in okayama#2, 138 in Sedo#4 and 135 in Sajanami, and it was decreased in the late transplanting. Fresh stem yield and dry stem yield were heaviest in October 25 transplanting, and it was light in the late transplanting. Judging from the results reported above, in optimum transplanting date of mat rush seemed to be before the October 25.

• Korean Journal of Clinical Laboratory Science
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• v.47 no.3
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• pp.147-152
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• 2015

The seasonal pattern of larvae, nymph and adult life stages for three tick species were studied for April-October, 2014. Haemaphysalis longicornis (610), Haemaphysalis flava (296) and Ixodes nipponensis (15) were collected from Pocheon by the dragging and flagging method. H.longicornis (254), H.flava (345) and I.nipponensis (15) were collected from Cheolwon in the same way. H.longicornis adults peaked in June while nymphs were more frequently collected from April through June. In contrast, H.longicornis larvae were collected only in September and October. H.flava adults were collected in April, September, and October while nymphs were collected from April through October. The nymphs peaked in April in Pocheon while May was the peak in Cheolwon. Larvae of H.longicornis and H.flava were collected only in September and October. I.nipponensis adults and nymphs were more frequently collected in April, while the larvae were not collected during that period. Collecting ticks by the dragging and flagging method provides estimates of population densities for life stages of the selected species and the associated disease risk. These results can be used to predict seasonal population densities of ticks and the prevalence of tick-borne pathogens.

• Korean Journal of Medicinal Crop Science
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• v.24 no.2
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• pp.110-114
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• 2016

Background: This study aimed to investigate the effect of harvest time on the growth, yield characteristics and loganin content in Dipsacus asperoides Wall. Methods and Results: Dipsacus asperoides seedlings were planted within a nursery environment in early May 2015 and harvested in early, middle and late October 2015, and early November 2015. Harvest time did not result significant differences in the plant height, stem diameter, branch length, leaf width and aboveground dry weight moreover, no significant differences were observed in root length, number of roots and root diameter. However, the diameter of lateral roots was greater in the harvests from the late October and period thereafter. The highest values of root dry weight and yield were recorded in early November. Specifically, the yield significantly increased from 205 kg/10 a (index: 100) in early October to 358 kg/10 a (index: 175) in early November, in terms of root part weight. Loganin contents of D. asperoides differed significantly among harvest times raging from 0.0766% in early October to 0.1704% in late November, thereby showing an increasing trend in later harvest times. Conclusions: These results suggest that the optimum harvest time for D. asperoides is early November, when the yield is the highest. Harvest time significantly affected loganin contents, which constantly increased from early October until early November.

• Journal of Korean Society of Forest Science
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• v.99 no.4
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• pp.528-533
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• 2010

Cage plots were established in 2008 to find the relationship between combination of tended Japanese red pine sapling and the habitation of Monochamus alternatus, a vector for pine wood nematode. Japanese red pine sapling tended at different times were successively put into the cage, and then the adult of Monochamus alternatus was put in June. Presence or absence of the larva was determined November. Sapling tendings were done at seven successive times in 2009, mid- and late February and March, mid-April, May and June. Some saplings were also tended in mid-October of 2008, the previous year of this experiment. The larva was found in all the saplings tended later than mid-March in 2009. No larva was found in the saplings tended in mid-October of 2008 and those in February of 2009. In case of the combination the by-products of mid-February and late March of 2009 and mid-October of 2008, the larva was found in the by-product of mid-February and late March of 2009, but those in mid-October of 2008 was not. When the saplings tended in mid-October of 2008 and mid- and late February of 2009 were put into the cage singly, the larva was found in all the saplings. Results indicated the mixture of the saplings tended at different times affected the habitation of Monochamus alternatus differently.