• Korean Journal of Agricultural and Forest Meteorology
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• v.22 no.1
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• pp.26-46
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• 2020

An irrigated-maize agroecosystem is viewed as an open thermodynamic system upon which solar radiation impresses a large gradient that moves the system away from equilibrium. Following the imperative of the second law of thermodynamics, such agroecosystem resists and reduces the externally applied gradient by using all means of this nature-human coupled system acting together as a nonequilibrium dissipative process. The ultimate purpose of our study is to test this hypothesis by examining the energetics of agroecosystem growth and development. As a first step toward this test, we employed the eddy covariance flux data from 2003 to 2014 at the AmeriFlux NE1 irrigated-maize site at Mead, Nebraska, USA, and analyzed the energetics of this agroecosystem by scrutinizing its radiation, energy and entropy exchange. Our results showed: (1) more energy capture during growing season than non-growing season, and increasing energy capture through growing season until senescence; (2) more energy flow activity within and through the system, providing greater potential for degradation; (3) higher efficiency in terms of carbon uptake and water use through growing season until senescence; and (4) the resulting energy degradation occurred at the expense of increasing net entropy accumulation within the system as well as net entropy transfer out to the surrounding environment. Under the drought conditions in 2012, the increased entropy production within the system was accompanied by the enhanced entropy transfer out of the system, resulting in insignificant net entropy change. Drought mitigation with more frequent irrigation shifted the main route of entropy transfer from sensible to latent heat fluxes, yielding the production and carbon uptake exceeding the 12-year mean values at the cost of less efficient use of water and light.

• Journal of Gifted/Talented Education
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• v.27 no.1
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• pp.81-96
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• 2017

This study was to examine the passion profiles and direct, indirect, and total effects of music valuation(MV), passion for music (i.e., harmonious passion, obsessive passion), and satisfaction in music(SM) on music accomplishment(MA) of musically talented high school students in Korea. Of the 599 musically talented high school students surveyed from Gyonggi, Chungnam, and Busan in South Korea, 524 completed and returned the questionnaires yielding a total response rate of 87.48%. Students with high harmonious passion(HP) and high obsessive passion(OP) were classified as high passion students(Nhigh passion=228), where as those with low HP and low OP were classified as low passion students(Nlow passion=5). Students with high passion had higher MV and higher SM than those with high HP or low passion. Moreover, those with high passion had higher music accomplishment than those with high HP, high OP, or low passion. Students with high HP had higher MA and SM than those with low passion. MV affected MA through both HP and OP, and also SA. HP and OP also affected MA and SA. SM directly affected MA. Total effects of HP on MA were higher than those of OP, SM, and MV. The indirect effect of HP on MA were higher than those of OP. Findings indicated that the more students have a HP, the more they showed higher SM and MA when they engaged in music activity with higher MV. Future research is need to replicate these findings with professional musicians at higher levels of expertise.

• Korean Journal of Agricultural Science
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• v.41 no.4
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• pp.327-334
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• 2014

Light intensity is one of the most important requirements for plant growth, affecting growth, development, survival, and crop productivity. Sunlight is the main energy source on Earth which is energy used by photosynthesis to convert light energy to chemical energy. In this study, the light use efficiency and photosynthetic characteristics of high-quality rice cultivars were evaluated after shading on ripening stage. For the study, we treated of three levels of shade (0, 50 and 70%) on rice at ripening stage and two levels of nitrogen (9 and 18 kg/10a) used three high yielding rice cultivars, such as Boramchan, Hopum, and Honong. The shade was given for the respective plots from heading up to harvesting. We were performed to determine growth survey, SPAD and chlorophyll fluorescence every 10 days interval after shading on ripening stage. At harvest stage, grain yield and yield components were determined. Results of analysis of the results representing the maximum photosynthetic efficiency of PSII, Fv/Fm, and SPAD were decreased by depending on the time at full sunlight. But shade treatments were not changed and a significant difference among cultivars did not appear. Compared with the full sunlight, shade treatments significantly delayed ripening rate and decreased rice quality of cultivated rice. Therefore, rice yield, can be reduced in proportion to the shading density is apparent, the rate of decrease was not observed difference between varieties, when protected from light 70%, and decreased to less than 50%. The adverse effects of low light intensity on the yield and yield components were not able to significantly minimize by the nitrogen level.

• Korean Journal of Soil Science and Fertilizer
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• v.1 no.1
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• pp.1-5
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• 1968

A low yielding paddy soil was water logged at $30{\pm}2^{\circ}C$ with soluble starch as a easily decomposable organic matter for 3 weeks in the laboratory. The relation of pH and Eh changes and soluble iron, manganese and silica was investigated. The experimental results obtained were summarized as follows; 1. When organic matter was applied, reduction of the soil was severer, that is, Eh value was lower by 200 mv. for a week in the beginning of submergence. 2. pH of the untreated soil was dropped a little just after submergence, and then gradually increased to 60. When treated, pH was increased due to abrupt drop of Eh in the beginning but decreased to 4.5 after a week, and became constant at this pH value. 3. Slight increase in soluble iron, manganese and silica was observed in the untreated soil whereas soluble iron, manganese and silica in the treated soil were increased about 20, 10, and 3 times, respectively. 4. When soluble starch was treated, pH and soluble silica or manganese was highly correlated[($H^+$) and Mn ${\gamma}=0.734^{**}$, ($H^+$) and $SiO_2$ ${\gamma}=0.923^{**}$] and below pH 5.0, release of these element was rapidly increased.

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.1
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• pp.50-57
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• 1985

An attempt was made to determine the optimum levels of sewage sludge application for seogwangbyeo in the farmer's field. 1. Optimum amount of sewage slude application was 338kg/11a at the fertilizer (N-P-K) level of 15-10-10kg/10a, 430kg/10a at that of 7.5-10-10kg/10a and 544kg/10a at no fertilizer. 2. Number of tillers during all growing period were increased with amounts of sewage sludge and/or chemical fertilizers. 3. Panicles per hill was increased but percent ripeness was decreased with the application of increasing level of sewage sludge and/or chemical fertilizer. In particular, the decrease of ripeness among yield-related components sotood out as an important one to be solved for higher yield. 3. Panicles per hill was increased but percent ripeness was decreased with the application of increasing level of sewage sludge and/or chemical fertilizer. In particular, the decrease of ripeness among yield-related components stood out as an important one to be solved for higher yield. 4. Ripeness was remarkably decreased in high nitrogen content of soil and rice plant under heavy amounts of sewage sludge and/or chemical fertilizer. 5. Ripeness that had direct effect on yield showed significantly possitive correlation with the content of $SiO_2$ and $SiO_2/N$ in rice plant from 25 days after transolanting to harvesting stage. 6. Maximumutillzation of nitrogen and its production efficiency of absorbed nitrogen in sewage sludge were 16.6% and 31.9kg (Yield/kg, N) at the level 15-10-10kg/10a as fertilizer with amounts of sewage sludge application, and 19.0% and 31.8kg (yield/kg, N) at sewage sludge application without fertilizer.

• Korean Journal of Soil Science and Fertilizer
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• v.8 no.2
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• pp.69-80
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• 1975

Relationships between yield and various nitrogen efficiencies, between efficiencies and between efficiency and nitrogen uptake amount of rice plant were proposed and tested using data from N.P.K simple trials about 30 to 50 locations, for three years. Established relationships are well in accordance with experimental results by showing highly significant correlations between them. The overall indications are that high yielding capacity of fields with fertilizer application, depends primarily on high fertilizer nitrogen uptake by increasing fertilizer use efficiency (Eu), secondly the efficiency (Ef) of absorbed fertilizer nitrogen (Nf) and fertilization efficiency (Fe) and also depends much on nitrogen efficiency for grain yield (E) to great extend and that the efficiency (Es) of soil nitrogen (Ns) contributes to E more than Ef does. All nitrogen efficiencies are negatively correlated with the uptake amount of corresponding nitrogen and counterpart efficiency. Es and Ef could be determined firstly by difference method and secondly E versus Cs (Cs=Ns/Ns+Nf) plotting and thirdly E-Cs plotting with labelled fertilizermethod using the equation E=Es Cs+B where B=Ef Cf but a constant under the given condition and at last Y-Ns plotting with labelled fertilizer using Eq Y=$Es{\cdot}Ns+B$ where B=$Ef{\cdot}Nf$. Es which seems not much variable from field to field is mostly greater (about 80% of tested fields) than Ef which is much variable and depends much on fertilizer form. The relationships tested and well agreed are as follows: 1. Y=$Es{\cdot}Ns+Ef{\cdot}Nf$ (Y is yield) 2. E=$Es{\cdot}Cs+Ef{\cdot}Cf$ where Cf=Nf/Nf+Ns 3. E=b-aN where E=E, Es or Ef and N=N, Ns or Nf respectively, (E=Y/N, N=Nf+Ns), b is theoretical maximum under the given system and a is tangent at N=O of the curve, Y=EN. 4. Fe=Ef Eu and Se=$Es{\cdot}Eu$ where Se is efficiency of soil available nitrogen. 5. E=$(Se{\cdot}Cs+Fe{\cdot}Cf)/Eu$ 6. Y=$Es{\cdot}Eu{\cdot}Sf+Ef{\cdot}Eu{\cdot}Fn$or Y=$Es{\cdot}Eu{\cdot}Ea{\cdot}Sn+Ef{\cdot}Eu{\cdot}Fn $where Sf=$Ea{\cdot}Sn$, Ea is soil available nitrogen equivalent to fertilizer(Sf) divided by total soil nitrogen (Sn).

• Korean Journal of Soil Science and Fertilizer
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• v.6 no.4
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• pp.231-237
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• 1973

Eeffect of temperature (3-day or 7-day treatment under $15^{\circ}C$, $20^{\circ}C$ and $25^{\circ}C$) on chlorophyll, nitrogen and potassium content in the second leaf blade from top of IR667 line (Suwon 213 and 214) and leading local varieties (Jinheung and Paldal) was investigated at the end of nursery, maximum tillering and flowering stage using phytotron. 1. Chlorophyll content was higher in IR667 line than in the local at $25^{\circ}C$ but reversed at $20^{\circ}C$ or $15^{\circ}C$ and chlorophyll a/b value was always high in the local. 2. Chlorophyll content per fresh weight decreased with growth and low temperature effect was greater at the end of nursery and on chlorophyll a than on chlorophyll b. 3. Chlorophyll a/b value increases with the increase of chlorophyll content and the increasing rate of chl. a/b value per chlorophyll increment tends to decrease under unfavorable condition. This decrease is greater in low temperature sensitive IR667 than local varieties. 4. According to chlorophyll retention value IR667 line was weaker at low temperature. 5. The content of total nitrogen or soluble nitrogen (methanol soluble) was decreased by low temperature. 6. Chl. (a+b)/S-N value decreased with growth and seemed not to be greatly affected by temperature and always higher in the local. 7. Potassium content (total or methanol soluble) tends to decrease at low temperature and soluble K increased with chlorophyll content. 8. High yielding ability of IR667 seems to be attributable to its high chlorophyll content at high temperature and easy leaf discoloration by low temperature or by nitrogen depression of IR667 seems to be attributable to the low Chl./S-N value.

• Korean Journal of Agricultural and Forest Meteorology
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• v.18 no.3
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• pp.99-108
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• 2016

The shuttle breeding of Korean winter wheat has been able to develop high-yielding and day-length-intensive varieties with a wide range of ecologic adoption. However, the phenology of winter wheat has been changed due to recent rises in the winter temperature of Toluca and increasing frequency of high temperatures. We defined two wheat groups (group II and III) with vernalization and evaluated the impact of cold exposure duration and heading ratio due to changes in sowing dates by measuring changes in cold exposure duration and corresponding heading states of each group. The wheat cultivars were sown on three dates in two years. The cold exposure requirement of wheat sown on 6 November 2013 was unfulfilled. The cold exposure requirement of wheat sown on 22 November and 6 December 2013 was fulfilled. However, in 2014, the cold exposure requirement of wheat sown on 5 and 20 November was fulfilled, but that of wheat sown on 5 December was unfulfilled. The differences for the two early November sowings were because winter temperature rises, which caused high temperatures in 2013, whereas early November 2014 saw normal temperatures for the area. The heading ratio of group II did not show a clear difference among the three sowing dates, while the heading ratio of group III was reduced by about half. This implies that the efficiency of shuttle breeding of group III will be high since it showed strong sensitivity to changes in sowing dates. We calculated future sowing dates of each group under near future climate scenarios; the future available sowing dates of group II were projected, but the dates of group III were never estimated in the temperature rise scenario in Toluca. Our findings suggest that change of sowing dates should be considered in the strategy for shuttle breeding of Korean winter wheat.

• Investigative Magnetic Resonance Imaging
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• v.13 no.2
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• pp.161-170
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• 2009

Purpose : A parallel imaging method provides us to improve temporal resolution to obtain three-dimensional (3D) MR images. The objective of this study was to optimize three 3D MRI techniques by adjusting 2D SESNE factors of the parallel imaging method in phantom and human brain. Materials and Methods : With a 3 Tesla MRI system and an 8-channel phase-array sensitivity-encoding (SENSE) coil, three 3D MRI techniques of 3D T1-weighted imaging (3D T1WI), 3D T2-weighted imaging (3D T2WI) and 3D fluid attenuated inversion recovery (3D FLAIR) imaging were optimized with adjusting SESNE factors in a water phantom and three human brains. The 2D SENSE factor was applied on the phase-encoding and the slice-encoding directions. Signal-to-noise ratio(SNR), percent signal reduction rate(%R), and contrast-to-noise ratio(CNR) were calculated by using signal intensities obtained in specific regions-of-interest (ROI). Results : In the phantom study, SENSE factor = 3 was provided in 0.2% reduction of signals against without using SENSE with imaging within 5 minutes for 3D T1WI. SENSE factor = 2 was provided in 0.98% signal reduction against without using SENSE with imaging within 5 minutes for 3D T2WI. SENSE factor = 4 was provided in 0.2% signal reduction against without using SENSE with imaging around 6 minutes for 3D FLAIR. In the human brain study, SNR and CNR were higher with SENSE factors = 3 than 4 for all three imaging techniques. Conclusion : This study was performed to optimize 2D SENSE factors in the three 3D MRI techniques that can be scanned in clinical time limitations with minimizing SNR reductions. Without compromising SNR and CNR, the optimum 2D SENSE factors were 3 and 4, yielding the scan time of about 5 to 6 minutes. Further studies are necessary to optimize 3D MRI techniques in other areas in human body.

• Applied Biological Chemistry
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• v.50 no.4
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• pp.245-252
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• 2007

FTA (fault tree analysis), an analytical method for system failure management, was employed in the management of faults in running PCR analysis. PCR is executed through several processes, in which the process of PCR machine operation was selected for the analysis by FTA. The reason for choosing the simplest process in the PCR analysis was to adopt it as a first trial to test a feasibility of the FTA approach. First, fault events-top event, intermediate event, basic events-were identified by survey on expert knowledge of PCR. Then those events were correlated deductively to build a fault tree in hierarchical structure. The fault tree was evaluated qualitatively and quantitatively, yielding minimal cut sets, structural importance, common cause vulnerability, simulation of probability of occurrence of top event, cut set importance, item importance and sensitivity. The top event was 'errors in the step of PCR machine operation in running PCR analysis'. The major intermediate events were 'failures in instrument' and 'errors in actions in experiment'. The basic events were four events, one event and one event based on human errors, instrument failure and energy source failure, respectively. Those events were combined with Boolean logic gates-AND or OR, constructing a fault tree. In the qualitative evaluation of the tree, the basic events-'errors in preparing the reaction mixture', 'errors in setting temperature and time of PCR machine', 'failure of electrical power during running PCR machine', 'errors in selecting adequate PCR machine'-proved the most critical in the occurrence of the fault of the top event. In the quantitative evaluation, the list of the critical events were not the same as that from the qualitative evaluation. It was because the probability value of PCR machine failure, not on the list above though, increased with used time, and the probability of the events of electricity failure and defective of PCR machine were given zero due to rare likelihood of the events in general. It was concluded that this feasibility study is worth being a means to introduce the novel technique, FTA, to the management of faults in running PCR analysis.