• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.1
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• pp.59-68
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• 1994

The effects of silt and clay, water temperature and salinity on the metabolic activities: rates of respiration, filtration and nitrogen excretion in the clam, Mactra veneriformis, were investigated in ranges of $0{\sim}250ppm,\;15{\sim}25^{\circ}C\;and\;10{\sim}30\%0$ respectively. The weight specific respiration rate decreased with shell length and significantly declined at lower temperatures and lower salinity levels. Average respiration rates, filtration rates and ammonia excretion rates of the clam groups declined as water temperature was lowered. The respiration rate(R) and the filtration rate(F) decreased as the concentration of silt and clay(C) increased, the relationships between the two parameters were expressed as a regression line, R=a+b LogC and LogF=a+b LogC, respectively. On the rearing experiment treated with 50ppm of silt and clay, the relationship between the accumulative mortality(M) and the elapsed day(T) was $M=0.0186T^{2.7965}$, and the median lethal time was calculated at 16.8 days. From the rearing experiment, both rate of respiration and ammonia nitrogen excretion of experimental groups and control groups decreased with elapsed days, the rates of experimental groups, especially declined more compared with those of the control groups.

• Korean Journal of Food Science and Technology
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• v.44 no.4
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• pp.383-389
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• 2012

Green tea leaves grown in Jeju island were harvested at different times in 2010 and 2011. Green teas harvested in 2010 experienced higher effective accumulative temperature than green teas harvested in 2011. The free and bound volatile compounds in green tea were analyzed using headspace-solid phase microextraction gas chromatography (GC) and GC-mass spectrometry. All green teas contained the 6 major volatile compounds ${\alpha}$-methylbutanal, pentanal, (E)-2-hexen-1-ol, ${\beta}$-linalool, geraniol and ${\alpha}$-farnesene. After enzyme treatment, (Z)-3-hexen-1-ol, benzaldehyde, (Z)-3-hexenyl acetate, ${\beta}$-linalool and geraniol were increased in all green teas. (Z)-3-hexen-1-ol increased significantly in green tea harvested in 2010, and benzaldehyde increased widely in green tea harvested in 2011. However, the total volatile compounds in green teas harvested in 2011 were remarkably decreased in comparison to harvested in 2010. It was confirmed that free and bound volatile compounds in green tea are affected by low winter temperatures.

• Korean journal of applied entomology
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• v.47 no.4
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• pp.359-364
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• 2008

The development of Aulacorthum solani (Kaltenbach) was studied at temperatures ranging from 12.5 to $27.5^{\circ}C$ under $65{\pm}5%$ RH, and a photoperiod of 16:8 (L:D). Mortality of $1st{\sim}2nd$ nymph was higher than that of $3rd{\sim}4th$ nymph at the most temperature ranges whereas at high temperature of $27.5^{\circ}C$, more $3{\sim}4th$ nymph stage individuals died. The total developmental time ranged from 16.9 days at $12.5^{\circ}C$ to 6.6days at $22.5^{\circ}C$, suggesting that higher the temperature, faster the development. However, at higher temperature of $25^{\circ}C$ the development took 7.4 days. The lower developmental threshold temperature and effective accumulative temperatures for the total immature stage were $0.08^{\circ}C$ and 162.8 day-degreeslated development. The nonlinear shape of temperature rewas well described by the modified Sharpe and DeMichele model. When the normalized cumulative frequency distributions of developmental times for each life stage were fitted to the three-parameter Weibull function, attendance of shortened developmental times was apparent with in $1{\sim}2nd$ nymph, $3{\sim}4th$ nymph, and total nymph stages in descending order. The coefficient of determination $r^2$ ranged between 0.86 and 0.91.

• Korean journal of applied entomology
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• v.46 no.2
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• pp.213-219
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• 2007

The development of Schizaphis graminum (Rondani) was studied at various constant temperatures ranging from 15 to $32.5^{\circ}C$, with $65{\pm}5%$ RH, and a photoperiod of 16L:8D. Mortality of the $1_{st}-2_{nd}\;and\;the\;3_{rd}-4_{th}$ stage nymphs were similar at most temperature ranges while at high temperature of $32.5^{\circ}C$, more $3_{rd}-4_{th}$ stage individuals died. The total developmental time ranged from 13.8 days at $15^{\circ}C$ to 4.9 days at $30.0^{\circ}C$ suggesting that the higher the temperature, the faster the development. However, at higher end temperature of $32.5^{\circ}C$ the development took 6.4 days. The lower developmental threshold temperature and effective accumulative temperatures for the total immature stage were $6.8^{\circ}C$ and 105.9 day-degrees, respectively and the nonlinear shape of temperature related development was well described by the modified Sharpe and DeMichele model. The normalized cumulative frequency distributions of developmental period for each life stage were fitted to the three-parameter Weibull function. The attendance of shortened developmental times was apparent with $1_{st}-2_{nd}\;nymph,\;3_{rd}-4_{th}$ nymph, and total nymph stages in descending order. The coefficient of determination $r^2$ ranged between 0.80 and 0.87.

• Korean Journal of Medicinal Crop Science
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• v.5 no.2
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• pp.95-101
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• 1997

This study was conducted to investigate how a labor saving for conventional hand sowing and respond to major agronomic traits under different planting density in 1993 and 1994. Each trial was a randomized block split plot with row spacing as the main plots and hill spacing as subplots. Sowing rate appeared lower in 20 or 25cm hill spacing using machine seeder than in hand sowing. Sowing time required reduced more 121 hours per hectare in 60cm row, 20cm hill spacings using machine seeder than in hand sowing. Increasing row and hill spacings reduced number of seedling stand per unit $area(m^2)$. Both number of pods per plant and grain weight per plant and showed highly increase in wide planting. Best yield obtained in 60cm row, 20cm hill spacing using machine seeder. Accumulative mean air temperature was positively correlated with stem height, number of pods per plant and yield, otherwise accumulative rainfall was negatively correlated with ones. A highly significant negative correlation was showed between number of seedling stand per unit $area(m^2)$ and number of branches, number of pods per plant, grain weight per plant and yield. Yield was positively correlated with number of branches, number of pods per plant and grain weight per plant.

• Journal of Bio-Environment Control
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• v.29 no.4
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• pp.414-420
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• 2020

This study was carried out to investigate the growth characteristics of standard chrysanthemum 'Baekma', such as fresh weight, dry weight, and leaf area and to develop prediction models for the production greenhouse based on the growth parameters and climatic elements. Sigmoid regressions models for the prediction of growth parameters in terms of dry weight and leaf area were analyzed according to the number of the day after transplanting and the accumulate temperature during this experimental period. The relative growth rate (RGR) of the chrysanthemum was 0.084 g·g^-1·d^-1 on average during the period.The dry weight and leaf area of 'Beakma' increased exponentially according to the number of day after transplanting and the accumulated temperature, in the case of dry weight increased by an average of 39.1% until 63 days (accumulated temperature of 1601℃), after that dry weight increased by an average of 7.4% before harvest. The leaf area increased by an average of 63.3% until the 28th day after transplanting, and by an average of 6.5% until the 84th day before flower bud differentiation occurred, and increased by an average of 10.6% before harvest. This experiment can be used as a useful data for establishing a cultivation management system and a planned year-round production system for standard chrysanthemum "Baekma". To make a more precise growth prediction model, it will need to be corrected and verified based on various weather data including accumulated irradiation.

• Korean journal of applied entomology
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• v.44 no.4 s.141
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• pp.277-282
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• 2005

This study was conducted to investigate morphological characteristics and effects of temperature on the development of Piezodorus hybneri on soybean. The unibanded stink bug, Piezodorus hybneri, is a serious insect pest in soybean fields giving damage to seeds in pod and leaves of soybean lowering both quality and yield. Eggs were spherical and laid in two raws on the leaves and pods of soybean plants. Body lengths of females and males were 9.8 mm and 8.7 mm, respectively. Egg hatch rates were better in higher temperature within the range of examined temperatures, which ranged in $81.2{sim}93.2%$. The development periods of eggs at the temperatures of 20, 25, 30 and $35^{\circ}C$ were 10.7, 5.0, 4.0, and 3.0 days, respectively. Mean developmental periods of 1st, 2nd, 3rd, 4th and 5th nymphs at $25^{\circ}C$ were 3.2, 3.4, 3.4, 3.3 and 5.9 days, respectively. Development threshold and effective accumulative temperature were $13.3^{\circ}C$ and 65.5 DD (day degree) for egg stage, $9.9^{\circ}C$ and 322.8 DD for nymph stage, $10.7^{\circ}C$ and 386.4 DD from egg to adult, respectively. Oviposition began from 10 days after emergence at $25^{\circ}C$, and the longevity of female and male were 52.5 and 38.2 days, respectively. Total number of eggs and egg masses laid by a female at $25^{\circ}C$ were 496 and 21.3, respectively, The longevity of adult female was shortened with increasing temperature, whereas the total numbers of eggs laid by a female were decreased.

• Korean journal of applied entomology
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• v.53 no.4
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• pp.449-456
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• 2014

Life table analysis and temperature-dependent development experiments were conducted to understand the biological characteristics of the cabbage aphid, Brevicoryne brassicae (Linnaeus) on detached Tah Tsai Chinese cabbage (Brassica campestris var. narinosa) leaves at seven constant temperatures (15, 18, 21, 24, 27, 30 and $33{\pm}1^{\circ}C$; $65{\pm}5%$ RH; 16L:8D). Mortality was lowest at $24^{\circ}C$ with 18% and 0% at $1^{st}{\sim}2^{nd}$ and $3^{rd}{\sim}4^{th}$ nymphal stages, respectively. The developmental period of $1^{st}{\sim}2^{nd}$ nymphal stage was 8.4 days at $18^{\circ}C$, and it decreased with increasing temperature. The developmental period of the $3^{rd}{\sim}4^{th}$ nymphal stage was 6.7 days at $18^{\circ}C$. The lower threshold temperature calculated using a linear model was $7.8^{\circ}C$, and the effective accumulative temperature was 120.1DD. Adult longevity was 14.9 days at $21^{\circ}C$, and total fecundity was observed 58.5 at $24^{\circ}C$. According to the life table, the net reproduction rate was 47.5 at $24^{\circ}C$, and the intrinsic rate of increase and the finite rate of increase were 0.36 and 1.43, respectively, at $27^{\circ}C$. The doubling time was 1.95d at $27^{\circ}C$, and mean generation time was 7.43d at $30^{\circ}C$.

• Journal of Satellite, Information and Communications
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• v.12 no.3
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• pp.41-49
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• 2017

This paper will describe lunar lava tubes' five analyzed fields, such as geology, geomorphology, internal configuration, stability, communication and habitats requirements. This research gets through qualitative and qualitative data analysis as following results. A huge size and configuration differences between lunar lava tubes and earth one on geology and landform environments. Exo-genetics activities, such as meteorites, radiation, and sudden temperature bigger affect than Endo-genetic activities, such as effusion and earthquake of the lunar lava tubes. Landform and internal configuration of the lunar lava tubes due to the huge cave perilous landform that gravity difference have a technical limitation from internal approach and data obtain of the huge skylights and sinuous rilles. Stability of the lunar lava tubes deals with geology and landform. It was obvious geo-structural stability elements results generated on low rate of collapsed halls(skylights), low gravity, and relatively thick covers. In terms of the communication capability on the external and internal lunar lava tubes cordless communication techniques will overcome limitations of the sun-power generates supporting communication systems. Through this research it realized obvious differs between potential habitats possibility by accumulative theories by scholars and techniques of the lunar lava tubes. Especially, it is a favorable expectation throughout overcoming attempt on zero gravity, cosmo radiation, lunar dust of the exo-genetic limitations to the steep escarpment of skylights to approach and achieve techniques by the civil engineering, networking and GIS techniques as the endo-genetic environment treatment.

• Korean Journal of Environmental Agriculture
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• v.35 no.3
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• pp.202-210
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• 2016

BACKGROUND: This study was conducted to determine effects of ridging systems and plastic film mulch types on growth, yield, and profitability of potato (Solanum tuberosum L.) in spring cropping using paddy field and to suggest profitable ridging system and plastic mulch type.METHODS AND RESULTS: Two potato cultivars ('Goun', and 'Atlantic') were grown at paddy field located in Gangneung in spring. For treatments, ridging systems were one-row ridge (OR) and two-row ridge (TR). Mulch types were no-mulch (NM), black plastic film mulch (BPM), and transparent plastic film mulch (TPM). Emergence of sprout was affected by the mulch types and the fastest level was shown at TPM treatment. Accumulative soil temperature during sprouting was 16.2℃ higher at TR than at OR and also higher at TPM than at BPM or NM. Stem length was not affected by ridging systems or mulch types. Leaf area index (LAI) was influenced by mulch types, while not by ridging systems. The highest LAI was shown at TR with TPM and OR of BPM. There was no significant difference in specific gravity or dry matter rate by ridging systems and mulch types. Tuber yield was significantly influenced by ridging systems and mulch types. Mean tuber weight was heavier at OR treatment than at TR and also the heaviest at TPM among mulch types. The highest marketable yield was found at OR with BPM. Based on marketable tuber yield and market price, the highest income ratio in two cultivars was found at OR with BPM and it was 20~82% higher than the ratio at TR with TPM.CONCLUSION: In spring potato cropping using paddy field, OR with BPM is better for high yield and is more profitable for farmer's income than the conventional cultivation method, TR with TPM.