• International Journal of Industrial Entomology and Biomaterials
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• v.11 no.1
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• pp.1-12
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• 2005

Feed conversion efficiency contributes directly or indirectly on the cost benefit ratio of silkworm rearing and is considered to be an important physiological criterion for evaluating the superiority of silkworm breeds/hybrids. Food intake, assimilation and conversion of indigenous as well as exotic silkworm races are well studied by many researchers. In this review, an attempt has been made to consolidate works on feed conversion aspects of indigenous and exotic silkworm races. The paper also deals with the effect of various factors viz., nutritional, environmental and feeding on food assimilation and conversion parameters of mulberry silkworm.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.4
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• pp.366-371
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• 2011

The sea squirt Halocynthia roretzi is mainly cultured in Tongyeong, Southern coastal area of Korea. This study presents the physiological rates of respiration, excretion, feeding and assimilation efficiency of the sea squirt Halocynthia roretzi to analyze the SFG(scope for growth) and net growth efficiency, determined during 2007. Oxygen consumption and nitrogen excretion rates increased with a rise in temperature during the summer period whereas feeding rates decreased. The O:N ratio was high during winter(October to February). Assimilation efficiency showed an annual average of 75.4% during the experimental period, except during a period of elevated temperature in July to September(average $25^{\circ}C$). Net growth efficiency($K_2$) was 8.7 to 64.2% except for May to September, when temperature increased at the aquaculture farm. SFG was negative from May to September, reflecting high temperatures and low feeding rates during this period; its highest positive values occurred during winter.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.1
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• pp.44-48
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• 1999

Uptake, assimilation and translocation of nitrogen and dry matter assimilation and translocation in ten rice cultivars were observed in no-till direct-sown rice-vetch cropping system. There was a large degree of variation in N-uptake, grain yield, nitrogen translocation efficiency and dry matter assimilation and translocation in tested rice cultivars. Forty kg N/ha base, as compound fertilizer (21-17-21% of N-P-K) three weeks after sowing and 30 kg N/ha top-dressed at panicle initiation stage as in the form of (NH$_4$)$_2$$CO_2$ was applied. ‘Newbounet’, ‘Daesanbyeo’, and ‘Hwayeongbyeo’ showed higher translocation efficiency. The contribution of pre-heading dry matter assimilates to grain ranged from 33% to 99% of dry grain weight. Dry matter of ‘Calrose 76’ was lower than Newbounet but N content was higher in Calrose 76 than Newbonnet. By maturity, N content in vegetative parts declined considerably more than dry matter, vegetative and reproductive parts, N translocation efficiency, and N harvest index. Nitrogen translocation efficiency was greater in ‘Nonganbyeo’, Daesanbyeo, and Newbounet. Grain N concentration was positively correlated with N concentration or N content of the vegetative parts at heading in Nonganbyeo, ‘Dasanbyeo’, ‘Dongjinbyeo’, and Newbonnet. These results indicated that the greater amount of dry matter and N accumulated before heading stage, the higher translocation rates of dry matter to grain and the greater net losses at maturity.

• Korean Journal of Breeding Science
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• v.43 no.5
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• pp.349-359
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• 2011

Agriculture plays a vital role in the sustenance of human society and is the fundamental of developing economies. Nitrogen is one of the most critical inputs that define crop productivity. To ensure better value for investment as well as to minimize the adverse impacts of the accumulative nitrogen species in environment, improving nitrogen use efficiency of crop plants is of key importance. Efforts have been made to study the genetic and molecular biological basis as well as the biochemical mechanisms involved in nitrogen uptake, assimilation, translocation and remobilization in crops and model plants. This review gives an overview of metabolic, enzymatic, genetic and biotechnological aspects of nitrogen uptake, assimilation, remobilization and regulation. This review presents the complexity of nitrogen use efficiency and the need for an integrated approach combining physiology, quantitative trait genetics, system biology, soil science, ecophysiology and biotechnological interventions to improve nitrogen use efficiency.

• International Journal of Industrial Entomology and Biomaterials
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• v.9 no.2
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• pp.249-254
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• 2004

Dietary supplementation of sodium nitrate with different concentrations 50, 100, 200, 500, 700 and 1000 $\mu\textrm{g}$/ml of single, two, three and four feeds to fifth instar larvae of biovoltine NB$_4$D$_2$ race of the silkworm, B. mori resulted in significant increase in the food conversion, conversion rate and conversion efficiency $K_1$ and $K_2$. However, there were significant decrease in the food assimilation, assimilation rate and assimilation efficiency in the sodium nitrate treated groups as compared with that of the corresponding parameters of the carrier control. This indicates that the administration of sodium nitrate may stimulate metabolic activities, thereby influencing conversion of food into body weight in the bivoltine silkworm, B. mori.

• Journal of Environmental Science International
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• v.27 no.11
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• pp.1141-1154
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• 2018

Numerical experiments were carried out to investigate the effect of data assimilation of observational data on weather and PM (particulate matter) prediction. Observational data applied to numerical experiment are aircraft observation, satellite observation, upper level observation, and AWS (automatic weather system) data. In the case of grid nudging, the prediction performance of the meteorological field is largely improved compared with the case without data assimilations because the overall pressure distribution can be changed. So grid nudging effect can be significant when synoptic weather pattern strongly affects Korean Peninsula. Predictability of meteorological factors can be expected to improve through a number of observational data assimilation, but data assimilation by single data often occurred to be less predictive than without data assimilation. Variation of air pressure due to observation nudging with high prediction efficiency can improve prediction accuracy of whole model domain. However, in areas with complex terrain such as the eastern part of the Korean peninsula, the improvement due to grid nudging were only limited. In such cases, it would be more effective to aggregate assimilated data.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.3
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• pp.287-295
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• 2013

The growth, respiration, ingestion, and ecological efficiencies of Hexagrammos otakii larvae and juveniles reared on different diets and temperatures were estimated. A factorial experiment using two diets [non-enriched hatched Artemia nauplii (NEA) and enriched Artemia nauplii (EA)] crossed with two temperatures [natural seawater temperature (NT, $5.1-8.5^{\circ}C$) and heated seawater (HT, $13{\pm}0.5^{\circ}C$)] was conducted to investigate growth and energy budgets of Hexagrammos otakii larvae and juveniles. The energy used by larvae and juveniles for 6 weeks was calculated using data on ingestion, growth, respiration, excretion, and egestion. In the NT trials, the energy used for growth by larvae and juveniles was 0.121 and 0.129 Kcal in the NEA and EA treatments, respectively. Assimilation efficiency at NT were 78.0% and 80.2% in the NEA and EA trials, respectively. Gross growth efficiency ($K_1$) were 60.5% and 62.3% and net growth efficiency ($K_2$) was 77.56% and 77.71% in the NEA and EA trials, respectively. In the HT trials, the energy used for growth by juveniles was 0.189 and 0.212 Kcal in the NEA and EA trials, respectively. Assimilation efficiency at HT was 86.4% and 95.1% in the NEA and EA trials, respectively. Values of $K_1$ and $K_2$ at HT were 69.5% and 80.43%, respectively, in the NEA trials, and 73.9% and 77.66%, respectively, in the EA trials. These results suggest that enriched Artemia nauplii and higher temperatures ($13{\pm}0.5^{\circ}C$) are effective for rearing larvae and juveniles of H. otakii.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.3
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• pp.268-274
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• 2010

The aim of our study was to investigate the interactive effects of container size and nutrient supply on plant growth, chlorophyll synthesis, transpiration, $CO_2$ assimilation, water use efficiency (WUE), and nutrient uptake of vinca plant (Catharanthus roseus). A complete experiment utilizing four concentrations of fertilizer and three volumes of containers was conducted. As the container size was increased, the plant height, leaf area, and dry weight of vinca significantly increased regardless of fertilizer level. The leaf area and dry weight of vinca were highly sensitive to the container size. However, the chlorophyll contents of vinca 20 days after the transplant significantly increased with decreasing container sizes and increasing fertilizer concentrations. Significant differences in transpiration and $CO_2$ assimilation occurred with the use of differentfertilizer solutions, but the highest values for transpiration and $CO_2$ assimilation were in plants grown in the 15 cm-diameter containers. The highest water use efficiency was observed in the plants grown in 10 cm-containers with 4 dS/m of fertilizer, and there were no significant differences in WUE values among container sizes with fertilizer concentrations of 0, 1, or 2 dS/m. No significant difference in nutrient uptake was observed among the fertilizer levels or among the container sizes. However, at a fertilizer concentration of 4 dS/m, the uptake of several nutrients, including N, P, K, Ca, Mg, B and Fe, was higher in small containers than in larger ones.

• Journal of Environmental Science International
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• v.19 no.8
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• pp.983-999
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• 2010

Wind power energy is one of the favorable and fast growing renewable energies. It is most important for exact analysis of wind to evaluate and forecast the wind power energy. The purpose of this study is to improve the performance of numerical atmospheric model by data assimilation over a complex coastal area. The benefit of the profiler is its high temporal resolution and dense observation data at the lower troposphere. Three wind profiler sites used in this study are inhomogeneously situated near south-western coastal area of Korean Peninsula. The method of the data assimilation for using the profiler to the model simulation is the three-dimensional variational data assimilation (3DVAR). The experiment of two cases, with/without assimilation, were conducted for how to effect on model results with wind profiler data. It was found that the assimilated case shows the more reasonable results than the other case compared with vertical observation and surface Automatic Weather Station(AWS) data. Although the effect of sonde data was better than profiler at a higher altitude, the profiler data improves the model performance at lower atmosphere. Comparison with the results of 4 June and 5 June suggests that the efficiency with hourly assimilated profiler data is strongly influenced by synoptic conditions. The reduction rate of Normalized Mean Error(NME), mean bias normalized by averaged wind speed of observation, on 4 June was 28% which was larger than 13% of 5 June. In order to examine the difference in wind power energy, the wind power density(WPD) was calculated and compared.

• Journal of Korean Society for Atmospheric Environment
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• v.22 no.E2
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• pp.89-98
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• 2006

Two tobacco cultivars (Nicotiana tabacum L.), Bel-B and Bel-W3, tolerant and sensitive to ozone, respectively, were grown in a greenhouse supplied with charcoal filtered air and exposed to 200 ppb ozone for 4 hr. Effects on chlorophyll fluorescence, net photosynthesis, and stomatal conductance are described. Quantum yield was calculated from chlorophyll fluorescence and the initial slope of the assimilation-light curve measured by the gas exchange method. Only the sensitive cultivar, Bel-W3, developed visual injury symptoms on up to 50% of the $5^{th}$ leaf. The maximum net photosynthetic rate of ozone-treated plants was reduced 40% compared to control plants immediately after ozone fumigation in the tolerant cultivar; however, photosynthesis recovered by 24 hr post fumigation and remained at the same level as control plants. On the other hand, ozone exposure reduced maximum net photosynthesis up to 50%, with no recovery, in the sensitive cultivar apparently causing permanent damage to the photosystem. Reductions in apparent quantum efficiency, calculated from the assimilation-light curve, differed between cultivars. Bel-B showed an immediate depression of 14% compared to controls, whereas, Bel-W3 showed a 27% decline. Electron transport rate (ETR), at saturating light intensity, decreased 58% and 80% immediately after ozone treatment in Bel-B and Bel-W3, respectively. Quantum yield decreased 28% and 36% in Bel-B and Bel-W3, respectively. It can be concluded that ozone caused a greater relative decrease in linear electron transport than maximum net photosynthesis, suggesting greater damage to PSII than the carbon reduction cycle.