• Korean Journal of Organic Agriculture
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• v.22 no.4
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• pp.731-742
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• 2014

In the current study, we investigated effects of a combination of earthworm casting, environment-friendly by-product fertilizer, and cultivation soil of Gymnocalycium mihanovichii in a heavy fertilizing culture on diameter, height, numbers of tubercles, and chemical properties of soil thereby elucidating optimal mixture ratio for securing production as well as providing nutrients throughout cultivation period. The Gymnocalycium mihanovichii var 'Ihong', one of grafted cactus for export (Rootstock: 9 cm, Scion: $1.5{\times}1.3cm$ grafted cactus) was cultured in plastic houses of Agricultural Technology Center located in Naegok-dong, Seocho-gu, Seoul from June, 2013 through December, 2013. For the control group, a mixture of sand and fertilizer (50:50) was used as this ratio is widely utilized in farmhouses. In contrast, a variety mixtures of sand and earthworm casting that was produced with food wastes was compared; the mixture ratios were 80:20, 60:40, 40:60, 20:80, and 0:100 and pH for these mixtures were found to be similar each other (ranging between 7.1 and 7.4) which is in an appropriate range (pH 6.5-7.5) for cultivation of G. mihanovichii. The organic content was increasing along with increasing contents of earthworm casting ratio while it was lower than the treatment practice group (32-43 mg/kg vs. 55 mg/kg). The content of exchangeable cation was also increasing as the ratio of earthworm casting was elevated; although levels of $K^+$, $Na^+$, and $Mg^{2+}$ were lower than the treatment practice group, the level of $Ca^{2+}$ was higher ($9.1cmol^+/kg$ and $11.5-33.7cmol^+/kg$ in the treatment practice group and the earthworm casting group, respectively). Three months after grafting, diameters of G. mihanovichii were compared with the control group; consequently, there was a significant difference noted in between the earthworm casting group and the control group (31.39 mm vs. 32.46-37.59 mm). After 5 months, growth characteristics of G. mihanovichii were evaluated. Similarly, the diameter of G. mihanovichii was significantly increasing in the group with higher ratio of earthworm casting treatment (32.63 mm vs. 32.49-37.59 mm). The height of tubercles was 2.63 mm in the control group while it was significantly elevating along with the ratio of earthworm casting mixture. The more numbers of tubercles, the more incomes for farm-houses; as results, higher mixture ration of earthworm casting resulted more numbers of tubercles compared to the control group (2.7 vs. 3.2-8.3 ea). In particular, in the earthworm casting groups with 80% and 100% ratios, the numbers of tubercles were 6.2 and 8.3 ea, respectively, which is 2.5 times more than those of the control group. These results indicate that earthworm casting treatment may be utilized in G. mihanovichii farming houses for short term production of tubercles. In the group with 40% and 60% of earthworm casting mixture, the numbers of tubercles were found to be 4.5 and 4.8 ea, respectively which is higher than the control group as well; in these groups, there were no issues with soil drainage as well as moss formation. Given the analysis results of growth characteristics of G. mihanovichii, it was concluded that 40% and 60% of earthworm casting mixture might be the optimal ratios.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.26 no.5
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• pp.477-492
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• 1993

In order to investigate the n-3 highly unsaturated fatty acids (n-3HUFA) requirement of the Korean rockfish Sebastes schlegeli, two experiments were conducted in the flush-out aquarium system. 1. Effects of different dietary fatty acids on growth and feed efficiency Efficacy of different fatty acids on the Korean rockfish was investigated by feeding diets containing each of the different fatty acids, 12:0, 18:1n-9, 18:2n-6, 18:3n-3, and n-3HUFA for 9 weeks. The best growth and feed efficiency were obtained from the fish fed diet containing n-3HUFA (P<0.05). 2. n-3HUFA requirement Requirement of dietary n-3HUFA for the Korean rockfish (5.9 g in mean body weight) was investigated with the test diets containing different levels of n-3HUFA ranging from $0\%$ to $4.0\%$ at $8\%$ dietary lipid level. After 6 weeks of feeding experiment, fish performance and fatty acid composition of liver were studied. Growth was significantly improved with increasing dietary n-3HUFA level up to the $0.9\%$ in the diet (P<0.05). Higher values of lipid content, 18:1/n-3HUFA ratio of polar lipid of liver and hepatosomatic index were observed in the fish fed n-3HUFA deficient diets. The groups of fish fed lower levels of dietary n-3HUFA showed higher 18:1 and love. n-3HUFA (EPA+DHA) levels in polar lipid of the liver. The data obtained in these experiments indicated that dietary n-3HUFA was essential for the Korean rockfish, and required level of n-3HUFA was around $0.9\%$ in diet.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.8
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• pp.1165-1171
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• 2015

In this study, we examined the effects of cultivation adaptability and product quality of aronia (fruit of Aronia melanocarpa) cultivated in various domestic regions. Extracts of aronia cultivated in various domestic regions and Poland were measured for their total sugar contents, acidities, total polyphenol contents, anthocyanin contents, and antioxidant activities using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays. Our results showed that aronia extracts from the two countries had similar sugar contents, acidities, and anthocyanin contents. Anthocyanin is an important functional component of Aronia melanocarpa. Extracts of aronia from the two countries contained cyanidin-3-galactoside (65.5~69.1%) as the major anthocyanin compound. Aronia cultivated in C region showed higher polyphenol content (121.5%) than Poland aronia and we measured of antioxidant activities by DPPH ($IC_{50}$) and FRAP assay. Aronia cultivated in C region showed the highest antioxidant activity and polyphenol contents. Cultivation conditions of C region had sufficient sunshine and soil with pH of 6.5. From the above results, Korean aronia had similar activities with Poland aronia, which suggests that it can be a new potential development source and high technological foods.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.6
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• pp.920-926
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• 2010

Marine alga, Chlorella vulgaris, was extracted by chloroform-methanol (2:1, v/v) solvents for lipid extraction at $35^{\circ}C$ for five hours (HCM-35) and its process was compared with conventional lipid extraction condition such as chloroform-methanol (2:1, v/v) at $65^{\circ}C$ for one hour (CM-65). This low temperature extraction process showed that 80% of total lipid was extracted and its residues contained relatively unchanged amounts of intact proteins and other minerals as well as amino acid profiles. Interestingly enough, the weight fraction of carbohydrate in the residues slightly increased due to less denaturation at low process temperature. The biological activities of the residues such as cytotoxicity and immune cell growth activation were not much changed after being extracted. The sensory evaluation were found to be very favorable for being used as a food additive and/or food supplement. This result could also help to maintain the economic feasibility of utilizing marine resources in food and other relevant industries.

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.2
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• pp.121-127
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• 1985

This study was designed to gain practical data on the use of soil conditioners for more efficient water managements and to establish the optimum levels of structural properties for soil conditioning. A sandy loam and a silt loam soil were each treated with two different soil conditioners, hydrophobic Bitumen or hydrophilic Uresol. The perspex tube 34 cm long were packed homogeneously with air dried soil up to 2 cm below the top, then covered over 2 cm of treated or untreated aggregates. The infiltration rate into the soil columns was measured under simulated rainfall condition. The evaporation study was carried out in the wind tunnel, and the changes of soil moisture distribution of the columns following and during the evaporation were determined by a gamma ray scanner. The infiltration rate of water into the soil column was increased to 18.7-50.8% by the Uresol treatment but it was decreased to less than 25% of control by the Bitumen treatment. Evaporation was decreased to 22.0-68.1% by the Bitumen treatment and to 38.7-68.4% by the Uresol treatment. The water use efficiency of Uresol treated column was increased to more than twice as much as that of untreated soil. Aggregate stability and wetting angle were related to water infiltration and evaporation. A positive and highly significant logarismic relationship was found between the infiltration rate and stability index-wetting angle, evaporation rate and instability index-wetting angle. It was considered that the structural stability is more important than wetting angle. This is true because the structural stability is always positively correlated to water saving, however wettability is positively correlated to the infiltration, and negatively correlated to water saving during the evaporation.

• Journal of Bio-Environment Control
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• v.17 no.1
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• pp.43-50
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• 2008

This study was conducted to investigate the proper supplied conditions of sodium selenate supplied by fertigation to improve functionality of major western vegetables; beet, broccoli, cabbage lettuce, celery, and parsley in highland. In this work, the growth and content of minerals, ascorbic acid, nitrate, and selenium were measured in western vegetables that treated sodium selenate by different concentration, treatment time and treatment frequency. While there was not different in early growth of some western vegetables among different concentration of sodium selenate; 1,2, 5 and $20\;mg{\cdot}L^{-1}$, at 20 days after treatment, the fresh weight was reduced 33% at cabbage lettuce,47% at broccoli, and 74% at parsley compared control in $5\;mg{\cdot}L^{-1}$ treatment. But the fresh weight of beet and celery reduced just 20% and 15% compared control in even $20\;mg{\cdot}L^{-1}$. The ascorbic acid of cabbage lettuce, celery, and beet increased as sodium selenate concentration increased, so that of cabbage lettuce showed 1.2 times compared control in $20\;mg{\cdot}L^{-1}$ treatment and also that of beet and celery increased 10%. But the ascorbic acid of broccoli and parsley was not influenced by treated sodium selenate. As the concentration of sodium selenate increased, the nitrate contents decreased regardless of crops compared control. This reduced effect of nitrate was highest in cabbage lettuce, followed by beet and celery. The mineral contents, such as K, Ca, and Mg, decreased in all crops, as the concentration of sodium selenate increased. The potassium content showed an obvious negative correlationship with the concentrations of sodium selenate regardless of crops, but the magnesium and calcium content did not show significant difference between treatments. The selenium content increased in proportion as increasing sodium selenate concentrations. The broccoli, celery and parsley treated $20\;mg{\cdot}L^{-1}$ sodium selenate showed 24.4 times, 76.4 times, and 560 times higher than control, respectively. When the sodium selenate supplied to some western vegetables in different growth stage, the selenium content increased 1.3 times and 1.4 times higher in early stage than in late stage in cabbage lettuce and broccoli, respectively. However in parsley and celery, the selenium content showed the highest in middle stage. The selenium content increased in proportion as increasing the sodium selenate treatment frequency, but in above 10 times treatment, the increased effect alleviated in parsley, celery, and cabbage lettuce. On the contrary, the selenium content of broccoli increased constantly as treatment frequency increased.

• Korean Journal of Soil Science and Fertilizer
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• v.37 no.2
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• pp.74-82
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• 2004

This study was conducted to estimate the optimum application rate of fertilizer N based on $NO_3-N$ concentration in soils for tomato (Lycopersicon esculentum Mill.) cultivation in plastic film house. Tomato plants were cultivated with and without fertilizer in twelve soils which have different concentrations of $NO_3-N$ ranging from 46 to $344mg\;kg^{-1}$. Dry weight (DW) of above-ground part of tomato with no fertilizer ranged from 28.9 to $112.5g\;plant^{-1}$, depending on N-supplying capability of soils. The soil $NO_3-N$ was positively correlated with DW ($r=0.83^{**}$) and N uptake ($r=0.78^{**}$) by tomatoes in no fertilizer treatment, and negatively correlated with fertilizer effciencies resulted from the differences of DW and N uptake between fertilized and non-fertilized plot. The relationships between soil $NO_3-N$ concentration and DW, N uptake, and fertilizer efficiency were analyzed to determine the critical levels of soil $NO_3-N$ for tomato cultivation. The limit critical levels of soil $NO_3-N$ were estimated to be more than $280mg\;kg^{-1}$ for no application of fertilizer N and to be less than $50mg\;kg^{-1}$ for recommended application of fertilizer N. These critical levels of soil $NO_3-N$ were nearly the same as those calculated from regression equation between electrical conductivity(EC) and soil nitrate for critical levels of EC in recommendation equation of fertilizer N for tomato under the plastic film house by NationaI Institute of Agricultural Science and Technology. Consequently, the optimal application rate of ferdilizer N for tomato cultivation in the soils containing $NO_3-N$ concentration between $280mg\;kg^{-1}$ and $50mg\;kg^{-1}$ was estimated by the equation Y = -0.4348X＋121.74, where Y is the percent(%) to the recommended application rate of N fertilizer and X is the soil $NO_3-N$ concentration ($mg\;kg^{-1}$).

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.3
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• pp.161-169
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• 2005

With various Korean domestic soybeans, growth and yields analysis were conducted to select the suitable soybean cultivars for cultivation in paddy field. Distinctive aspects of the soybean growth were observed in paddy field such as retarded growth of top plants and roots, relatively higher T/R ratio followed by overgrowth of top plant. However, growth and yields were significantly different among the cultivars showing 134kg/10a in Paldokong and 385 kg/10a in Doremikong. At V5. and R2 stage, highly positive correlations $(r=0.76^{**}\~0.91^{**})$ were observed between leaf area and dry weight of top plant and/or root. T/R ratio was negatively correlated with dry weight of root $(r=-0.37^*)$ at V5 stage, while significantly correlated with leaf area $(r=-0.37^{**})$ and dry weight of top plant $(r=0.65^{**})$at R2 stage. Among the characters, only 100-seed weight was significantly correlated with yield. Considering the growth characters, 37 cultivars could be included in 3 different groups and genotypic properties such as maturity and growth habit were similar in each group. Nine cultivars in group 1 showed retarded growth from V5 to R2 stage, relatively lower T/R ratio, and good seed ripening. Average yields of the cultivers was 257kg/10a. In group 2, 12 cultivars showed higher T/R ratio due to overgrowth of top plant and lowest average yields (230 kg/l0a) due to poor seed ripening. Sixteen cultivars in group 3 grew fast from V5 to R2 stage representing late maturity traits, low T/R ratio, and good seed ripening. Average yields of the cultivars was highest among groups showing 270kg/l0a. In results, stable self-sufficiency of soybean yields could be expected by selective cultivation with high yielding cultivars ranging from 301 to 385kg/10a, such as Shinpaldalkong 2, Sohokong, Doremikong, Keumkangkong, Bukangkong, Dajangkong, and Geomjeongkong 2, or with cultivars included in group 3.

• Journal of Korean Society for Atmospheric Environment
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• v.24 no.2
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• pp.196-205
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• 2008

Variability in vertical ozone and meteorological profiles was measured by 2Z electrochemical concentration cells (ECC) ozonesonde at Bangyi in Seoul ($37.52^{\circ}N$, $127.13^{\circ}E$) during June $6{\sim}9$, 2003 in odor to identify the vertical distribution of ozone and its relationship with the lower-atmospheric structure resulted in the high ozone concentrations near the surface. The eight profiles obtained in the early morning and the late afternoon during the study period clearly showed that the substantial change of ozone concentrations in lower atmosphere(${\sim}5\;km$), indicating that it is tightly coupled to the variation of the planetary boundary layer (PBL) structure as well as the background synoptic flow. All profiles observed early in the morning showed very low ozone concentrations near the surface with strong vertical gradients in the nocturnal stable boundary layer due to the photochemical ozone loss caused by surface NO titration under very weak vertical mixing. On the other hand, relatively uniform ozone profiles in the developed mixing layer and the ozone peaks in the upper PBL, were observed in the late afternoon. It was noted that a significant increase in ozone concentrations in the lower atmosphere occurred with the corresponding decrease of the mixing height in the late afternoon on June 8. Ozone in upper layer did not vertically vary much compared to that in PBL but changed significantly on June 6 that was closely associated with the variation of synoptic flows. Interestingly, heavily polluted ozone layers aloft (a maximum value of 115 ppb around 2 km) were formed early in the morning on 6 through 7 June under dominant westerly synoptic flows. This indicates the effects of the transport of pollutants on regional scale and consequently can give a rise to increase the surface ozone concentration by downward mixing processes enhanced in the afternoon.

• Journal of Intelligence and Information Systems
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• v.17 no.4
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• pp.95-108
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• 2011

TThis is a study of the personalization method that intelligently adapts the level of clustering considering purchasing index of a customer. In the e-biz era, many companies gather customers' demographic and transactional information such as age, gender, purchasing date and product category. They use this information to predict customer's preferences or purchasing patterns so that they can provide more customized services to their customers. The previous Customer-Segmentation method provides customized services for each customer group. This method clusters a whole customer set into different groups based on their similarity and builds predictive models for the resulting groups. Thus, it can manage the number of predictive models and also provide more data for the customers who do not have enough data to build a good predictive model by using the data of other similar customers. However, this method often fails to provide highly personalized services to each customer, which is especially important to VIP customers. Furthermore, it clusters the customers who already have a considerable amount of data as well as the customers who only have small amount of data, which causes to increase computational cost unnecessarily without significant performance improvement. The other conventional method called 1-to-1 method provides more customized services than the Customer-Segmentation method for each individual customer since the predictive model are built using only the data for the individual customer. This method not only provides highly personalized services but also builds a relatively simple and less costly model that satisfies with each customer. However, the 1-to-1 method has a limitation that it does not produce a good predictive model when a customer has only a few numbers of data. In other words, if a customer has insufficient number of transactional data then the performance rate of this method deteriorate. In order to overcome the limitations of these two conventional methods, we suggested the new method called Intelligent Customer Segmentation method that provides adaptive personalized services according to the customer's purchasing index. The suggested method clusters customers according to their purchasing index, so that the prediction for the less purchasing customers are based on the data in more intensively clustered groups, and for the VIP customers, who already have a considerable amount of data, clustered to a much lesser extent or not clustered at all. The main idea of this method is that applying clustering technique when the number of transactional data of the target customer is less than the predefined criterion data size. In order to find this criterion number, we suggest the algorithm called sliding window correlation analysis in this study. The algorithm purposes to find the transactional data size that the performance of the 1-to-1 method is radically decreased due to the data sparity. After finding this criterion data size, we apply the conventional 1-to-1 method for the customers who have more data than the criterion and apply clustering technique who have less than this amount until they can use at least the predefined criterion amount of data for model building processes. We apply the two conventional methods and the newly suggested method to Neilsen's beverage purchasing data to predict the purchasing amounts of the customers and the purchasing categories. We use two data mining techniques (Support Vector Machine and Linear Regression) and two types of performance measures (MAE and RMSE) in order to predict two dependent variables as aforementioned. The results show that the suggested Intelligent Customer Segmentation method can outperform the conventional 1-to-1 method in many cases and produces the same level of performances compare with the Customer-Segmentation method spending much less computational cost.