• Journal of Science Education
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• v.36 no.2
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• pp.235-250
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• 2012

This paper aims to find out whether or not elementary school students recognize and understand scientific units that they encounter in their everyday life. To select appropriate units for the survey, first, scientific units in elementary textbooks of science and other science related subjects were analyzed. Then it was examined how these units were related to the learners' daily life. The participants in the current survey were 320 elementary school 6th graders. A questionnaire consisted of 11 units of science, such as kg for mass, km for distance, L for volume, V for voltage, s for time, $^{\circ}C$ for temperature, km/h for speed, kcal for heat, % for percentage, W for electric power, pH for acidity, which can often be seen and used in daily life. The students were asked to do the following four tasks, (1) to see presented pictures and select appropriate scientific units, (2) to write reasons for choosing the units, (3) to answer what the units are used for, and (4) to check where to find the units. The data were analyzed in terms of the percentage of the students who seemed to well recognize and understand the units, using SPSS 17.0 statistical program. The results are as follows: Regarding the general use of the units, it was revealed that almost the same units were repeated in science and other subject textbooks from the same grade. With an increase of the students' grade more difficult units were used. As for the use of each unit, it was found that they seemed to relatively well understand what these units kg, km, L, $^{\circ}C$, kcal, km/h, and W stand for, showing more than 91% right. However, the units of V, s, in particular, %, and pH did not seem to be understood. With respect to the recognition of the units, most students did not recognize such units as L for volume and pH for acidity, probably because the units are difficult at the elementary level in comparison to other scientific units. The students indicated that schools were the best place where they could learn and find scientific units related to life, followed by shops/marts, newspapers/broadcasting, streets/roads, homes, and others in that order. The results show that scientific unit learning should be conducted in a systematic way at school and that teachers can play a major role in improving students' understanding and use of the units.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.spc1
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• pp.35-41
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• 2006

This study was conducted to establish the post-harvest management system in rice. Harvested hulled rice was gathered into large-scale bag and combine bag, in which the rice quality and the influence on quality change were investigated on various storage periods and moisture contents. Moisture content of hulled rice ranged from 23.7% to 28.8% on different harvest times, which grew lower as harvesting time was delayed. When desiccation was retarded hulled rice in large scale bag was changed in color and emitted an of offensive odor in 3 days and that in combine bag showed similar symptom in 4 days. Inner temperature in large scale bag was changed a lot when the storage period was prolonged and also the moisture content was higher while that in combine bag increased regularly corresponding to the moisture content at the time of harvest. Moisture content of hulled rice stored in large-scale bag increased 2 days after harvest and the more moisture content showed the more increased tendency, while in the case of combine bag the moisture content was not changed much whether the hulled rice contained low or high moisture content in harvesting. As desiccation was delayed fatty acid increased much more in large-scale bag than in combine bag even though protein and amylose contentwere not changed. As desiccation was delayed more and hulled rice contained moisture more in harvesting head rice ratio of brown rice decreased and green-kerneled rice and damaged grain ratio increased and quality of milled rice also became deteriorated. As a result, desiccation day to minimize the deterioration of rice quality was estimated 1-2 days in large scale bag and 2-3 days in combine bag after harvesting.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.3
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• pp.182-191
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• 2020

A field test and a phytotron study were performed over two years to examine whether rice varieties originated from higher altitude areas have lower optimum grain filling temperatures for yield improvement than the varieties from South Korea. Three varieties originated from North Korea and three varieties from northern China were compared to the same number of varieties from South Korea. In a field study, the optimum grain filling temperatures over 40 days after heading were 22.6 - 23.0℃, 21.5 - 22.3℃, and 21.5 - 23.6℃ for the varieties from North Korea, northern China, and South Korea, respectively, resulting in no significant difference among varietal groups. Meanwhile, the heading dates of the early maturing varieties from North Korea and China were 7 - 12 days earlier than that of the early maturing Odae variety from South Korea during the first transplant of 2017. The phytotron study, in which different temperature regimes were imposed from flowering/fertilization to harvest with constant daily mean temperatures, revealed that milled rice weight did not decrease under low temperatures, even at 16℃, compared to that at 22℃. At the fourth transplant in the field study, mean temperature lower than 10℃ appeared before rice grains were fully developed, resulting in yield reductions. It was concluded that rice varieties adaptable to high-altitude areas do not have lower optimum grain filling temperatures but, instead, possess shorter growth durations. It was further suggested that the optimum grain filling temperature of rice observed under natural conditions could be attributed to the lowering temperature at the late filling stage under temperate climatic conditions.

• Horticultural Science & Technology
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• v.31 no.3
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• pp.359-365
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• 2013

Chrysanthemum is one of the most popular ornamental plants worldwide. Recently, lots of new and novel chrysanthemum varieties have been developed using mutagenesis. However, there was no study for comparison of tissue culture condition among the mutant varieties derived from one original variety, until now. This study was conducted to compare the efficient regeneration condition of the two chrysanthemum mutant varieties, 'ARTI-purple' and 'ARTI-queen'. Two different flower parts (disk and ray florets) at the unopened and early blooming stages were used for comparison of regeneration condition on MS medium supplemented with combinations of three growth regulators (BA, NAA, and IAA). The highest regeneration rate was identified on the NAA and BA combination when the disk florets at unopened blooming stage are used. The best optimum combinations of growth regulators were identified as NAA $1.0mg{\cdot}L^{-1}$ and BA $0.5mg{\cdot}L^{-1}$ at 'ARTI-purple', which displayed 47.9% regeneration. However, regeneration of 'ARTI-queen' was the highest as 25.6% at NAA $2.0mg{\cdot}L^{-1}$ and BA $1.0mg{\cdot}L^{-1}$. There results indicate that there is a difference for the optimum regeneration condition between the mutant varieties derived from one original variety. These results will be useful for construction of efficient regeneration system of diverse chrysanthemum mutants developed by mutation breeding.

• Journal of Life Science
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• v.19 no.2
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• pp.241-248
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• 2009

In order to investigate the effects of synbiotics on change of chemical composition and fermentation characteristics of total mixed ration (TMR), eight TMRs fermented by synbiotics composing the anaerobic microbes (bacteria, yeast, mold) were alloted to the experimental treatments. Treatments were composed of untreated synbiotics(US), bacterial synbiotics (BS), yeast synbiotics (YS), mold synbiotics (MS), bacterial and mold synbiotics (BMS), yeast and mold synbiotics (YMS), bacterial and yeast synbiotics (BYS), and bacterial, yeast and mold synbiotics (BYMS). After 7 days of anaerobic fermentation, fermented-TMRs were exposed to air during 1, 3, 5, 7, 14 and 21 days. One hundred forty four (8 treatments ${\times}$ 6 exposing days ${\times}$ 3 replications) fermented- TMRs were manufactured by vinyl bag sized of 43 cm by 58 cm. The results obtained were as follows. Moisture contents of the fermented TMRs anaerobically ranged from 41% to 45%, and was similar to those of basal TMRs. As results of anaerobic fermentation, the concentration of crude protein was decreased by 11.7% to 14.8% in the untreated sample, while was rather increased by 11% when the TMR was fermented with BMYS. And also BMYS treatment showed decreases by 32% for crude fiber, 15.5% for NDF and 26.1% for ADF. Internal temperature of fermented-TMRs was highest at 7 day of exposing in the air. The pH of fermented-TMR juice was significant difference betweentreatments after 7 day of exposing in air, and that of BMS was highest at 14 day after exposing in air (P<0.05). Acid buffering capacity was increased in proportion to the exposing day of TMR, and peaked at 7 or 14 days after exposing. Ammonia concentration of fermented-TMRs was highest at 5 day after exposing in the air. Individual volatile fatty acid of fermented-TMR juice was very low level in all treatments. Although BMYS treatment to TMR inclined to increase in crude protein and decrease in fibers, but there were no positive effects on the fermentation characteristics after exposing in the air by supplementation of anaerobic synbiotics to TMR.

• Journal of Bio-Environment Control
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• v.22 no.1
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• pp.1-6
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• 2013

This study was conducted to examine the effects of coir, peatmoss, and red clay (20%) + peatmoss (80%) media on quality and drainage solution in hydroponics of Solanum lycopersicum 'Mascara'. The tomato seedlings were planted in media on 29 April, and supplied with Yamazaki's tomato solution of EC $2.0dS{\cdot}m^{-1}$ and pH 6.5. Tomato fruits were harvested from 13 June to 24 August. Drainage amount decresed when solar radiation and air temperature were high. However, drainage amount were not different among coir, peatmoss, and red clay + peatmoss media. The EC of drainage in red clay + peatmoss medium was higher than that in other media during the cultivation period. Also, soild state and available moisture content was more in red clay + peatmoss mediun than in coir or peatmoss media. The soluble solids of tomato fruits increased by 10~17% at $5.5^{\circ}Brix$ in red clay+peatmoss medium compared with $5.0{\sim}4.7^{\circ}Brix$ in coir or peatmoss media. Also, the acidity of fruits was the highest to 0.66% in red clay + peatmoss medium than the others. The total yield of fruits in red clay + peatmoss medium increased significantly by 9.1% at 8,428 kg than at 7,725 kg in peatmoss medium, and ratio of marketable yield was higher than the other media. Therefore, red clay (20%) + peat moss (80%) medium is recommend for growth and quality of fruits in hydroponics of Solanum lycopersicum 'Mascara'.

• The Korean Journal of Food And Nutrition
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• v.17 no.2
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• pp.111-119
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• 2004

A new type of drinkable yoghurt was prepared to develop a functional yoghurt. Skim milk containing 0.4-1.0％(w/v) water extract of omija(Schizandra chinensis Baillon) was fermented by the mixed strains of Lactobacillus acidophilus and Streptococcus thermophilus. Quality characteristics of the drinkable yoghurts were evaluated in terms of compositions, keeping-quality(pH, titratable acidity, number of viable cells) and sensory properties. The drinkable yoghurts added with water extract of Schizandra chinensis were composed of 2.92-3.03％ protein, 9.98-10.23％ lactose, 0.81-1.08％ fat, 16.21-16.64％ total solid, and 14.57-15.17％ solid-not-fat. The L values(brightness) were significantly lower in the yoghurts containing water extract of Schizandra chinensis than that of the control which had no water extract of Schizandra chinensis, while the a values(redness) and b values(yellowness) were significantly higher than those of the control. The pH, titratable acidity and number of viable cells of the lactic acid bacteria of all yoghurts were not changed during the storage at 4$^{\circ}C$ for 15 days, while the pH and titratable acidity were remarkedly changed during the yoghurts stored at 20$^{\circ}C$ for 15 days. The drinkable yoghurts containing 0.4％(w/v) water extract of Schizandra chinensis added 15％(w/v) oligosaccharide, or 0.6％(w/v) water extract of Schizandra chinensis added 20％(w/v) oligosaccharide had the highest sensory score in taste and overall acceptability among the treatments. From the results, Schizandra chinensis was a useful natural additive with the bioactive effect by provision of a acceptable physicochemical and sensory properties in the drinkable yoghurt.

• Korean Journal of Remote Sensing
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• v.33 no.6_2
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• pp.1119-1137
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• 2017

This study assessed the water provisioning and climate mitigation ecosystem services of the urban forest in Seoul and Gyeonggi-do. The ecosystem service assessment is conducted based on natural function, natural function and population, and natural function and the beneficiary of the ecosystem service. Then, the impact of climate change on ecosystem services is analyzed to figure out the sensitivity of the impact on the beneficiary when the natural function of forest destroys under climate change. Gyeonggi-do has higher function-based water provisioning ecosystem service than Seoul. And population-based water provisioning ecosystem service appears to be higher in the densely populated area. On the other hand, beneficiary-based water provisioning ecosystem service by applying both natural water supply function and beneficiary distribution appears different with the result of population-based water provisioning service assessment. In other words, regions with high beneficiary population show higher ecosystem service than those with a low beneficiary population even though they have the same water storage function. In addition, climate change has a negative impact on the water provisioning ecosystem service. Under climate change, water provisioning service is expected to decrease by 26%. For climate mitigation service, regions close to the forest seem to have a low temperature, which indicates their high climate mitigation service. The center of the city with high beneficiary population shows high beneficiary-based ecosystem service. The climate change impacts the forest growth to decrease which affect the beneficiary-based climate mitigation ecosystem service to decrease by 33%. From this study, we conclude that beneficiary-based function and ecosystem service assessment is needed as well as the supply-based classification of forest function suggested by Korea Forest Service. In addition, we suggest that not only supply-based function classification and ecosystem service assessment but also beneficiary-based function classification and ecosystem service assessment is needed for managing the urban forest, which has been destroyed by climate change. This will contribute to revaluing cases where a forest with low natural function but high beneficiary-based ecosystem service, which is not considered under the current forest function-based assessment system. Moreover, this could assist in developing a suitable management plan for the urban forest.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.1385-1390
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• 2006

외국에서 ASM 모델의 BNR 적용 연구결과를 국내 하수에 적용하기에는 하수농도, 온도, 슬러지농도 등이 국내와는 달라 적용상 무리가 있다. 본 연구에서 BNR 시뮬레이션을 위한 입력 자료로 활용되는 인자들은 IAWPRC task group에서 제안하는 값들을 사용하되 국내 하수성상에서 필요로 하는 인자들은 직접 실험을 통하여 부분적으로 구해냄으로써 모델 시뮬레이션의 신뢰도를 높이고자 하였다. F/M비의 변화량과 1/SRT과의 관계로부터, 종속영양미생물 생산계수 $Y_H$값을 구한결과, 0.40mg VSS/mg COD였다. 이것을 ASM No.2d에 적용하기 위하여 mg cell COD formed/mg COD oxidized 단위로 환산한 결과 0.58을 나타냈다. H 하수처리장의 1차 침전지 하수를 이용하여 호기성상태에서 OUR Test를 통한 미생물에 의한 유기물 섭취시 산소섭취율 변화를 측정하였다. 호기성상태와 무산소상태에서 구한 쉽게 분해되는 용존성유기물(Ss)값을 비교해보면 각각 35.5mg/L와 39.9mg/L로 약간의 차이는 있으나 유사한 값을 보여주고 있다. 시뮬레이션을 위한 동력학적 계수 중 무산소 상태에서 종속영양미생물의 ${\mu}_{max,H}$는 $3.56d^{-1}$로 나타났고, 호기성상태에서는 구하면 ${\mu}_{max,H}$는 $4.2d^{-1}$로 산출되었다. 종속영양미생물의 사멸계수 $b_H$를 구하기 위한 실험에서 초기 OUR의 10%이내가 될 때까지 걸린 시간은 7일정도가 걸렸으며, 사멸률 $b_H$는 $0.043hr^{-1}$로 나타났다. 독립영양미생물의 최대비성장률 ${\mu}_{max,A}$는 최대암모니아 섭취률을 이용하여 구한 결과 $0.65d^{-1}$로 나타났다.EX>$60%{\sim}87%$가 수심 10m 이내에 분포하였고, 녹조강과 남조강이 우점하는 하절기에는 5m 이내에 주로 분포하였다. 취수탑 지점의 수심이 연중 $25{\sim}35m$를 유지하는 H호의 경우 간헐식 폭기장치를 가동하는 기간은 물론 그 외 기간에도 취수구의 심도를 표층 10m 이하로 유지 할 경우 전체 조류 유입량을 60% 이상 저감할 수 있을 것으로 조사되었다.심볼 및 색채 디자인 등의 작업이 수반되어야 하며, 이들을 고려한 인터넷용 GIS기본도를 신규 제작한다. 상습침수지구와 관련된 각종 GIS데이타와 각 기관이 보유하고 있는 공공정보 가운데 공간정보와 연계되어야 하는 자료를 인터넷 GIS를 이용하여 효율적으로 관리하기 위해서는 단계별 구축전략이 필요하다. 따라서 본 논문에서는 인터넷 GIS를 이용하여 상습침수구역관련 정보를 검색, 처리 및 분석할 수 있는 상습침수 구역 종합정보화 시스템을 구축토록 하였다.N, 항목에서 보 상류가 높게 나타났으나, 철거되지 않은 검전보나 안양대교보에 비해 그 차이가 크지 않은 것으로 나타났다.의 기상변화가 자발성 기흉 발생에 영향을 미친다고 추론할 수 있었다. 향후 본 연구에서 추론된 기상변화와 기흉 발생과의 인과관계를 확인하고 좀 더 구체화하기 위한 연구가 필요할 것이다.게 이루어질 수 있을 것으로 기대된다.는 초과수익률이 상승하지만, 이후로는 감소하므로, 반전거래전략을 활용하는 경우 주식투자기간은 24개월이하의 중단기가 적합함을 발견하였다. 이상의 행태적 측면과 투자성과측면의 실증결과를 통하여 한국주식시장에 있어서 시장수익률을 평균적으로 초과할 수 있는 거래전략은 존재하므로 이러한 전략을 개발 및 활용할 수 있으며, 특히, 한국주식시장에 적합한 거래전략은 반전거래전략이고, 이 전략의 유용성은 투자자가 설정한 투자기간보다 더욱 긴 분석기간의 주식가격정보에 의하여 최대한 발휘될 수 있음을 확인하였다.(M1), 무역적자의 폭, 산업의 생산

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.11
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• pp.1678-1683
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• 2010

For extension of storage period of cabbage-kimchi, effects of heat treatment as well as nisin or yucca extract were examined on the growth of microbes. Firstly, when kimchi was heated at various temperatures in polyethylene plastic bottle or membrane pouch, the optimum inhibitory condition giving no sensory change was at $80^{\circ}C$ for 30 min in a plastic membrane pouch and this treatment made a reduction of $0.3\;log_{10}CFU/g$ in total microbes. The result showed that use of plastic bottle was inefficient due to low heat transfer rate. Interestingly, pasteurization of seasoning pastes at $80^{\circ}C$ for 30 min separately from cabbage resulted in better inhibitory effect reducing $0.5\;log_{10}CFU/g$ of total bacteria and $1.0\;log_{10}CFU/g$ of lactic acid bacteria, and this operation was regarded as a promising inhibitory method. Secondly, when nisin and yucca extract were separately added in kimchi, microbial growth was inhibited during storage period and their inhibition effects were enhanced at lower temperature.