• Korean journal of applied entomology
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• v.51 no.3
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• pp.235-243
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• 2012

Population dynamics of the American serpentine leafminer, Liriomyza trifolii (Burgess), were observed and modeled in order to compare the effects of air and tomato leaf temperatures inside a greenhouse using DYMEX model builder and simulator (pre-programed module based simulation programs developed by CSIRO, Australia). The DYMEX model simulator consisted of a series of modules with the parameters of temperature dependent development and oviposition models of L. trifolii were incorporated from pre-published data. Leaf surface temperatures of cherry tomato leaves (cv. 'Koko') were monitored according to three tomato plant positions (top, > 1.8 m above the ground level; middle, 0.9 - 1.2 m; bottom, 0.3 - 0.5 m) using an infrared temperature gun. Air temperature was monitored at the same three positions using a self-contained temperature logger. Data sets for the observed air temperature and average leaf surface temperatures were collected (top and bottom surfaces), and incorporated into the DYMEX simulator in order to compare the effects of air and leaf surface temperature on the population dynamics of L. trifolii. The initial population consisted of 50 eggs, which were laid by five female L. trifolii in early June. The number of L. trifolii larvae was counted by visual inspection of the tomato plants in order to verify the performance of DYMEX simulation. The egg, pupa, and adult stage of L. trifolii could not be counted due to its infeasible of visual inspection. A significant positive correlation between the observed and the predicted numbers of larvae was found when the leaf surface temperatures were incorporated into the DYMEX simulation (r = 0.97, p < 0.01), but no significant positive correlation was observed with air temperatures(r = 0.40, p = 0.18). This study demonstrated that the population dynamics of L. trifolii was affected greatly by the leaf temperatures, though to little discernible degree by the air temperatures, and thus the leaf surface temperature should be for a consideration in the management of L. trifolii within cherry tomato greenhouses.

• Horticultural Science & Technology
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• v.32 no.4
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• pp.484-492
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• 2014

We quantified the effects of the composition and concentration of fertilizer solutions on the growth and nutrient uptake of 'Maehyang' strawberry at the vegetative growth stage. Acid fertilizer (AF), neutral fertilizer (NF), and basic fertilizer (BF) with concentrations of 100 or $200mg{\cdot}L^{-1}$ based on N, were formulated and applied during the 100 days after transplanting, at which point crop growth and tissue nutrient contents were analyzed. The soil solutions were sampled every two weeks to measure the pH, EC and nutrient concentrations. BF was a more effective fertilizer compared to AF and NF for growth of 'Maehyang' strawberry when fertilizer concentrations were controlled to $100mg{\cdot}L^{-1}$. By contrast, the fresh and dry weights were greatest in the NF treatment when fertilizer concentrations were controlled to $200mg{\cdot}L^{-1}$. The tissue contents of N, P, and Na were 2.20, 0.51 and 0.10%, respectively, in the NF 200 treatment, and these were the highest among all treatments tested. The highest contents of K, Ca and Mg were 2.60% in AF 200, 0.95% in BF 200 and 0.45% in BF 100, respectively. During the fertilization period, the highest and lowest pHs were 6.13 in BF 100 and 4.92 in AF 200. The lowest EC was $1.376dS{\cdot}m^{-1}$ in BF 100 and the highest was $4.936dS{\cdot}m^{-1}$ in NF 200 treatments. The highest $NH_4{^+}$ concentrations in the soil solution occurred during the AF 200 treatment, followed by those with NF 200 and AF 100. When fertilizer concentrations were equal, AF treatment gave rise to the highest $Ca^{+2}$ and $Mg^{+2}$ concentrations, followed by NF and BF, until day 84 of fertilization. The BF treatments had the highest $NO_3{^-}$ concentrations followed by NF and AF. The trends for $PO_4^{-3}$ concentrations were similar in all fertilizer treatments when the fertilizer concentrations were equal. The above results indicate that neutral and basic fertilizers were most effective to promote 'Maehyang' strawberry growth when fertilizer solutions were controlled to low or high concentrations, respectively. These findings are useful for planning fertilization programs for vegetative propagation of 'Maehyang' strawberry.

• Journal of Animal Environmental Science
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• v.17 no.sup
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• pp.61-68
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• 2011

To assess the total cost with all stages of facilities, the feasibility of Life Cycle Cost (LCC) analysis was examined in this study to estimate the livestock manure treatment system and optimal decision making process. For the economic evaluation, the plant/equipment investment and annual operation cost of four Public Livestock Recycling Facilities, whose treatment capacity is 100 ton piggery manure per day, was compared. The initial cost was in the range of 2,699 million won to 3,202 million won, where T and E methods were highest and lowest, respectively. The annual operation cost was in the level of 378 million to 498 million won, which decreased in the following order : T method > J method > E method > B method. For the LCC analysis, 4.7% of interest rate, 3.13% of inflation rate, and 1.52% of net discount rate was considered by the data received from Bank of Korea and Statics Korea in the period of 2000 to 2009. Also, for the calculation of present value factor, the durable years of civil engineering & construction, machinery and electric instrument was 30 years, 10 years and 15 years, respectively. Based on these consideration, operation cost was in the range of 17,570 won/ton to 20,661 won/ton, and E method (17,570 won/ton) was economical and B method (20,661 won/ton) was non-economical. Though initial cost of T method was higher than that of B method, LCC analysis of T method was lower than that of T method due to the lower operation cost. Therefore, LCC analysis, which considers both initial cost and operation cost, is more reasonable evaluation method than either initial cost or annual operation cost. For the change of LCC analysis according to the uncertainty, the sensitivity analysis was carried out using fluctuation magnitude of discount rate in the period of 2000 to 2009. As a result, LCC analysis evaluated by discount rate was stable for the uncertain factors since the cost leadership did not change even though the sensitivity analysis varied. In summary, the economic evaluation using LCC analysis could be an efficient reference to choose the suitable livestock manure treatment plants. Furthermore, standardization of statement calculation for the actual cost analysis should be conducted and more detailed study is necessary to validate this summary. Therefore, the application of comprehensive technology evaluation, which considers LCC analysis, should contribute in obtaining objectivity and enhancing reliability for the 'Evaluation of Livestock Manure Treatment System and its Technology'.

• Korean Journal of Environmental Agriculture
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• v.37 no.1
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• pp.15-20
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• 2018

BACKGROUND: The global mean surface temperature change for the period of 2016~2035 relative to 1986~2005 is similar for the four representative concentration pathway (RCP)'s and will likely be in the range of $0.3^{\circ}C$ to $0.7^{\circ}C$. Climate change inducing higher temperature could affect not only crop growth and yield, but also dynamics of carbon in paddy field. METHODS AND RESULTS: This study was conducted to evaluate the effect of elevated temperature on the carbon dynamics in paddy soil and rice growth. In order to control the elevated temperatures, the experiments were set up as the small scale rectangular open top chambers (OTCs) of $1m(width){\times}1m(depth){\times}1m(height)$ (Type 1), $1 m(W){\times}1m(D){\times}1.2m(H)$ (Type 2), and $1m(W){\times}1m(D){\times}1.4m(H)$ (Type 3). The average temperatures of Type 1, Type 2, and Type 3 from July 15 to October 30 were higher than the ambient temperatures at $0.4^{\circ}C$, $0.5^{\circ}C$, and $0.9^{\circ}C$, respectively. For the experiment, Wagner's pots (1/2,000 area) were placed inside chambers. The pots were filled with loamy soil, and chemical fertilizer and organic compost were applied as recommended after soil test. The pots were flooded with agricultural water and rice (Shindongjin-byeo) was planted. It was observed that TOC (total organic carbon) of the water increased by the elevated temperatures and the trend continued until the late growth stage of the rice. Soil TOC contents were reduced by the elevated temperatures. C/N ratios of the rice plant decreased by the elevated temperature treatments. Thus, it was assumed that the elevated temperatures induced to decompose soil organic matter. Elevated temperatures significantly increased the culm length (P<0.01) and culm weight (P<0.05) of rice, but the number and weight of rice panicle did not showed significant differences. CONCLUSION: Based on the results, it was suggested that the elevated temperatures had an effect on changes of soil and water carbons under the possible future climate change environment.

• The Journal of Korean Society for School & Community Health Education
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• v.5
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• pp.107-122
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• 2004

To correctly plant the value of sex to the juvenile, we cannot overemphasize the importance of the sexual education in schools. Therefore, the study for teachers' consciousness and view of sex is also necessary, because they are subjects of education and role-models of sex of their students. Especially, if teachers are over fifty in age, it is more important, because it is obvious, as they are in positions of managers and directors of education, that their view of sexual value and consciousness are influencing the aim of education and the course of education. Hereby this study was conducted to check their sexual consciousness, attitude, and condition and to prepare for the basic data needed for the development of a sexual education program suitable to them. The methods of the survey of this study are applied by modifying or supplementing those of precedented studies. They are used after analyzing reliance of items according to Cronbach's $\alpha$ figure calculating law, and modifying or supplementing items lower in reliance. The questionnaire survey was conducted among 1,000 randomly selected from teachers working in middle and high schools in Korea from June 14th in 2004 to June 30th. The survey analyzed 632 questionnaires suitable to it. The outcomes of the survey of this study are like the following: First, the objects of the survey consist of 64.6% men and 35.4% women. Among them, 41.1% are under fifty and the rest are over fifty. As for the periods of marriage, 15.5% are unmarried, 16.3% are under ten years, 18.0% are between ten and twenty, and 50.2% are over twenty. Second, with reagard to sex, 25.6% admit the necessity of a heterosexual friend. 32.0% say that they are conservative to sex. 54.1% are taught sexual education. 67.1% attribute sexual education to nursing teachers. Third, among those who answer that they enoughly know the concept of sex, seenig by age, 25.0% are under fifty and 58.1% are over fifty. Seening by the periods of marriage, 9.2% are unmarried, 28.2% are under ten, 49.1% are between ten and twenty, and 59.0% are over twenty. Among those who answer that they enoughly know the concepts of sexual harassment and sexual violence, seenig by age, in the turns by above-mentioned order, each 47.7% and 76.3%. Seening by the periods of marriage, each 9.2%, 28.2%, 49.1%, and 59.0%. Fourth, among those who answer that "teachers also need sexual education and sexual counsel," by age, each92.7% and 91.4%. By the periods of marriage, each 89.8%, 95.2%, 89.4%, and 92.4%. As a matter of course, we can infer the necessity of the sexual education and sexual counsel for teachers. Fifth, among those who answer that they are satisfied with their sexuality, by age, each 41.1% and 61.3%. By the period of marriage, each 4.1%, 63.1%, 64.1%, and 61.5%. As for the sexual desire like spiritual intercourse, physical intercourse containing sexuality, by age, each 71.9% and 93.5%. By the periods of marriage, each 54.0%, 81.5%, 90.3%, and 93.0%. The survey shows that those over fifty and having long marriage are feeling the stronger desire towards sexuality. Through the outcomes of this survey, a few suggestions are possible: First, it is necessary to check of the teachers' view of sexual value and to study deep about the sexual tendency of them in twenties, thirties, and forties. It is to make them teach their students on the firm basis, and also to develop suitable sexual education and counsel program.

• Korean Journal of Weed Science
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• v.32 no.2
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• pp.85-97
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• 2012

To investigate the usefulness of freshwater alga Water-net (Hydrodictyon reticulatum, HR) as resources for production of fermentable sugars, the easiness of enzymatic saccharification was evaluated at first. When 6 plant materials (HR, Spirulina, Chlorella, Scenedesmus, Cladophora, Corn stover) were enzymatically hydrolyzed with 2% solid loading at the same condition, HR showed the highest ratio of saccharification based on glucose production. No milled HR was also completely saccharified at the amounts of optimal enzyme mixture. Glucose yield was not changed though the citrate buffer strength for saccharification was decreased from 0.1 M to 0.1 mM. Only about 10% yield reduction was observed compared to that of $120^{\circ}C$ treatment when HR was enzymatically hydrolyzed at room temperature. The saccharification was normally occurred at $37^{\circ}C$ and pH 6.5 which is general growth condition of fermentable microrganisms, suggesting that HR have a biomass characteristics applicable for the simultaneous saccharification and fermentation. The saccharification was occurred by more than 70~80% of one of the best condition although the supplied enzyme amounts was reduced to 1/10 volume. And the glucose yield by enzymatic hydrolysis was not decreased by 10% HR solid loading and began to decrease at more than 15% solid contents. Above these results show that HR is an interesting algal biomass which is relatively easy to be saccharified by hydrolyzing enzymes. In addition, HR is a flilamentous alga and very easy to be collected. Therefore, HR seems to be an useful and valuable resources in the economical production of fermentable sugars for manufacture of bio-chemical products.

• Weed & Turfgrass Science
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• v.3 no.2
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• pp.71-77
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• 2014

Surveys of weed species in paddy fields were conducted in Korea to identify weed occurrence from June to September 2013. Total 3,434 sites of paddy fields in 155 City/Gun, eight Provinces were investigated. From the nation-wide survey, 90 weed species in 28 families were identified and classified to 52 annuals, 3 biennials and 35 perennials. Based on the occurrence ratio, the most weed species belonged to Poaceae (18 species). 17, 8 and 6 weed species belonged to Cyperaceae, Scrophulariaceae and Polygonaceae, respectively, and these 49 weed species in the most four families accounted for 54% of total weed occurrence. The most dominant weed species in Korean paddy fields were Echinochloa spp. (17.4%), followed by Monochoria vaginalis (12.4%), Eleocharis kuroguwai (7.8%), Bidens tripartite (9.27%), Scirpus juncoides (6.2%) and Sagittaria sagittifolia (6.1%). This information could be useful for estimation of future weed occurrence, weed population dynamics and establishment of weed control methods in paddy fields of Korea.

• Journal of Aquaculture
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• v.10 no.3
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• pp.327-334
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• 1997

This study was conducted with Israeli strain of common carp to determine apparent protein, lipid and gross energy digestibility coefficients and apparent calcium and phosphorus availabilities of the following feedstuffs : steam-dried white fish meal (WFM-S), flame-dried white fish meal (WFM-F), brown fish meal (BFM), soybean meal (SBM), corn gluten meal (CGM), sesame meal (SSM), wheat flour (WFL), brewer's yeast (BY) and monocalcium phosphate (MCP). Test diets consisting of a 70:30 mixture of refoernce diet to test ingredient were utilized with chromic oxide as an external indicator. Fecal collection was made during 10 days before the end of feeding trial lasted for 27 days. The best weight gain and feed utilization were found in fish fed MCP containing test diet. Protein digestibility was high for most ingredients, ranging from 81.2% for BY to 91.9% for SBM, with the exception of SSM which was 77.6%. Lipid digestibility coefficients ranged 74% for CGM to 85.8% for two kinds of white fish meal. Digestible energy coefficients were generally high for fish meals, ranging from 77.4% for WFM-S to 81.3% for WFM-F, whereas those for plant feedstuffs were significantly (P<0.05) lower, from 64.5% for CGM to 70.6% for BY. Phosphorus availability from fish meals was variable with a low of 6.6% for WFM-F and a high of 13.6% for WFM-S. Phosphorus availability from SBM and BY was 7.3% and 57.2%, respectively. Calcium and phosphorus availabilities from MCP were 84.6% and 80.6%, respectively. These results provide more precise information concerning nutrients and energy utilization of Israeli strain of common carp and will allow ingredient substitutions in practical diet formulations based on levels of availabile protein and phosphorus.

• Journal of Bio-Environment Control
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• v.26 no.3
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• pp.227-234
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• 2017

This study aimed to investigate the nutrient solution developed by based on nutrient-water absorption rate of strawberry 'Maehyang' by comparing growth and yield for 8 months with 5 kinds of nutrient solution with different ion composition. Strawberry plants were planted at elevated bed and supplied with five kinds of nutrient solutions (RDA), Yamazaki, PBG, University of Seoul (UOS) and NewUOS from one month onwards. Five types of nutrient solution were supplied to the strawberry plants associated with EC $1.0dS{\cdot}m^{-1}$, pH 6.0, $150{\sim}300mL{\cdot}plant^{-1}$ per day. At 60 days after planting, leaf width and leaf petiole of the strawberry plants showed significant differences among nutrient solution types and photosynthesis was higher in RDA and NewUOS nutrient solution and lower in PBG nutrient solution. The EC of the drainage on vegetative growth stage was $0.7{\sim}0.8dS{\cdot}m^{-1}$, which is lower than the supplied EC level, and to $1.0-1.2dS{\cdot}m^{-1}$, afterwards. The pH of the drainage was higher in Yamzaki solution as 6.2~6.8, while the pH of the UOS nutrient solution was lower in 5.1~5.2. Nitrate content was most absorbed in vegetative growth stage and after flower clusters development. The potassium uptake was highest at the NewUOS followed by UOS and Yamazaki nutrient solution. At six months after -planting fresh weight and dry weight of shoot and root were higher in UOS and NewUOS nutrient solution than other nutrient solutions, and the dry matter ratio was lower at 43.5% in Yamazaki nutrient solution and 30.6% in NewUOS nutrient solution than other solutions. Length, width, weight, and sugar content of the strawberries harvested from December to February were unaffected by treatment, but yield was higher in NewUOS nutrient solution due to increasing fruit number and average weight. From March to May, number of fruit was higher in Yamazaki nutrient solution. In conclusion, there was no difference in the growth of 'Maehyang' when 5 nutrient solutions were grown under hydroponics. But in order to improve the marketability, the NewUOS nutrient solution is appropriate to use from planting to February and it is suitable to use Yamazaki nutrient solution after March when temperature is high and the amount of fruit set per inflorescence.

• Journal of Korean Society of Forest Science
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• v.97 no.3
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• pp.215-220
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• 2008

Recently, there has been a great deal of interest in the applications of plant-based extracts to both cosmetic and medicinal industries. The objective of this study was to investigate the anti-inflammatory and antimicrobial effect of P. rigida extracts by water and ethyl acetate. Anti-inflammatory and anti-microbial effect of P. rigida extracts by water and EtOAc were investigated by using nitrite scavenging ability, nitric oxide production and anti-microbial ability. In the test of nitrite scavenging ability, P. rigida extracts by water and EtOAc showed 88.7% and 99% at 100 ppm concentration, respectively. The cell viability was measured using the MTT assay at 24 hours after P. rigida extracts as shown in over 80%. Anti-inflammatory effect was examined in LPS stimulated RAW 264.7 cells. NO productions in LPS and P. rigida extracts stimulated group were decreased in a concentration and were dependent on time as compared with LPS stimulated. The water extracts showed the highest inhibition at the 100 ppm concentration. In anti-microbial activity test, the water extract with 3.0 mg/disc resulted in the clear zone of 14 mm, and ethyl acetate with that of 15 mm for Staphylococcus aureus. However, P. rigida extracts didn't show any growth inhibitory effect on Esherichia coli. These results indicate that the extracts of P. rigida have anti-inflammatory activities as a cosmeceuticals.