• KOREAN JOURNAL OF CROP SCIENCE
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• v.25 no.2
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• pp.6-14
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• 1980

One of the physiological disease, sudden wiliting of Yushin variety suggested that low sunlight, excessive nitrogen application, and highly reduced soil condions either singly or combined, might be possible causes of the disorder. Some visual symptom of sudden wilting are discoloration of leaves, development of nodal roots above the soil surface, total root rot, and lodging. Those observations led to the hypothesis that suffocation of root tissues was a direct cause of the wilting. The oxygen transport characteristics of Yushin, IR262 and Tongil were examined by two methods. First, Soil-cultured plants of the three varieties were subjected to paraffin treatment to decrease the oxygen supply from the air to root tissues through the soil-water system, liquid paraffin was applied to the water surface in the pots at panicle formation stage. In this experiment, sudden wilting was observed of Yushin and IR262 at about a week after the treatment, but Tongil remained green and healthy. Wilting-resistant variety Tongil had higher oxygen release, whereas the susceptible Yushin and IR262 had lower oxygen release. Second, the number and size of the air spaces in each internode were investigated in the 5th internode from the top, all three varieties have a similar number of air spaces, although the air spaces of Thongil were larger. In the 4th internode, Tongil had plenty air spaces, Yushin and one of the Yushin's parents IR262 had scanty or none. The observations indicated that the ability of Yushin and IR262 for oxygen transport is very limited compared with that of Tongil. The limited oxygen supply due to poor development of air space in internode of rice plants may cause suffocation of root tissues, weaken metabolic activity of the tissues, and induce root rot, subsequently inducing sudden wilting and lodging under unfavorable weather, soil and cultural conditions.

• Microbiology and Biotechnology Letters
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• v.48 no.2
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• pp.205-214
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• 2020

Cyanobacteria are microorganisms which have important roles in the nitrogen cycle due to their ability to fix nitrogen in water and soil ecosystems. They also produce valuable materials that may be used in various industries. However, some species of cyanobacteria may limit the use of water resources by causing harmful algal blooms in water ecosystems. Many culture collection depositories provide cyanobacterial strains for research, but their systematic preservation is not well-developed in Korea. In this study, we developed a method for the cryopreservation of the cyanobacteria Trichormus variabilis (syn. Anabaena variabilis), using alginate microcapsules. Two approaches were used for the experiments and their outputs were compared. One of the methods involved the cryopreservation of cells using only a cryoprotectant and the other used the cryoprotectant within microcapsules. After cryopreservation for 35 days, cells preserved with both methods were successfully regenerated from the initial 1.0 × 10⁵ cells/ml to a final concentration of 6.7 × 10⁶ cells/ml and 1.1 × 10⁷ cells/ml. Irregular T. variabilis shapes were found after 14 days of regeneration. T. variabilis internal structures were observed by transmission electron microscopy (TEM), revealing that lipid droplets were reduced after cryopreservation. The expression of the mreB gene, known to be related to cell morphology, was downregulated (54.7%) after cryopreservation. Cryopreservation using cryoprotectant alone or with microcapsules is expected to be applicable to other filamentous cyanobacteria in the future.

• Journal of Korean society of Dental Hygiene
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• v.5 no.2
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• pp.201-218
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• 2005

The purpose of this study was to examine how dentists perceived dental coordinators including their education, hiring criteria, working condition and job. It's basically attempted to help define the job and role of 5 and to suggest how they should be nurtured. The subjects in this study were dentists at dental hospitals and clinics where dental coordinators were employed among approximately 200 dental institutions in Seoul, Cyeonggi province and Incheon. After a survey was conducted in June 2005, answer sheets from 99 respondents were analyzed. The findings of the study were as follows: 1. Regarding education for dental coordinators, 99.9% of the dentists investigated felt the need for separate education programs for dental coordinators, 42.4% knew what would-be dental coordinators learned about, and 81.8% considered it necessary for them to take intermediate or higher courses. An organization affiliated with the Korea Dental Hygienists Association was viewed as the best institute to educate dental coordinators, and educational institutes that included a department of dental hygiene was looked upon as the second best one. 68.7% believed that dental coordinators should take an official examination to test their qualifications, and concerning educational subsidy, the largest group of the dentists thought that a certain amount of subsidy should be provided. 2. As for coordinator hiring, the top priority was the impression(look) of applicants(55%), followed by adjustability to existing employees(24.5%) and professional competency(17.3%). As to the route of hiring, 41.4 percent, the largest group, reeducated some of existing employees, and dental hygienists were regarded as the best personnels to serve as a coordinator. Concerning job performance, they put the most emphasis on interpersonal relationship, which was followed by executive ability, impression and career, 58.6% the largest group, believed that dental coordinators should have a three-year or higher career to work at a dental institute. 3. As to working conditions, 75.7%, the largest group, paid dental coordinators based on their job performance, and 23.2%, the second largest group, had their pay equal to that of dental hygienists, 88.9% allowed them to determine their own retirement age. 4. In regard to their perception of dental coordinators, the largest number of the dentists considered it necessary for them to keep receiving education(4.29), and the second largest group felt that they served to enhance the image of dental institutes(4.18). The third largest group thought that they contributed to letting patients more satisfied with the quality of dental services. But they tended not to agree that their turnover rate was low(3.04), and they didn't find them to receive appropriate education, either(3.10). 5. The current major job of coordinators associated with customer services was handling appointments with customers(91.9%), treating unsatisfied customers(85.9%), and controling waiting time(84.8%). Regarding self-management, coordinators directed their energy into having good manners(89.9%), acquiring fundamental dental knowledge(84.8%), and learning how to treat customers(83.8%). Concerning hospital affairs handling, they were most responsible for information desk(87.9%), which was followed by receiving(86.9%). As a result of investigating what type of job the dentists hoped dental coordinators to fulfill in consideration of their career, their age and type of investment, the dentists wanted them the most to speak a foreign language, which belonged to the field of self-management.

• Analytical Science and Technology
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• v.13 no.4
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• pp.494-503
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• 2000

A 21-residue peptide corresponding to amino acids 84-104 of $p16^{INK4A}$, the tumor suppressor, has been synthesized and its structure was studied by Circular Dichroism, $^1H$ NMR spectroscopy and molecular modeling. A p16-derived peptide (84-104 amino acids) forming stable complex with CDK4 and CDK6 inhibits the ability of CDK4/6 to phosphorylate pRb in vitro, and blocks cell-cycle progression through G1/S phase as shown in the function of the full-length p16. Its NMR spectral data including NOEs, $^3J_{NH-H{\alpha}}$ coupling constants, $C_{\alpha}H$ chemical shift, the average amplitude of amide chemical shift oscillation and temperature coefficients indicate that the secondary structure of a p16-derived peptide is similar to that of the same region of full-length p16, which consists of helix-turn-helix structure. The 3-D distance geometry structure based on NOE-hased distance and torsion angle restraints is characterized by ${\gamma}$-turn conformation between residues $Gly^{89}-Leu^{91}$(${\varphi}_{i+1}=-79.8^{\circ}$, ${\varphi}_{i+1}=60.2^{\circ}$) as evidenced in a single crystal structure for the corresponding region of p18 or p19, but is undefined at both the N and C termini. This compact and rigid ${\gamma}$-turn region is considered to stabilize the structure of p16-derived peptide and serve as a site recognizing cyelin dependent kinase, and this well-defined ${\gamma}$-turn structure could be utilized for the design of anti-cancer drug candidates.

• Applied Biological Chemistry
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• v.49 no.3
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• pp.243-247
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• 2006

The biological activity of functional food source with thyme extracts were examined. Total phenol contents in the 60% ethanol extracts $(26.8{\pm}0.35\;mg/g)$ with thyme leaf was higher than water extracts $(25.7{\pm}0.20\;mg/g)$. This HPLC analysis is significant in that physiological activity is related with phenolic compound content such as rosemarinic acid, quercetin and chlorogenic acid. Electron donating ability was shown as 90.1% in the water extracts and 77.7% in the 60% ethanol extracts. Antioxidant protection factor of 60% ethanol extracts was higher than water extracts. Helicobacter pylori of the water extracts from thyme leaves did not have antimicrobial activity, but the 60% ethanol extracts revealed the high antimicrobial activity as 9 mm of clear zone in $50\;{\mu}g/ml$ of phenol content, 10 mm in $100\;{\mu}g/ml$, 13 mm in $150\;{\mu}g/ml$ and 16 mm in $200\;{\mu}g/ml$, respectively. Angiotensin converting enzyme inhibition activity showed no inhibition activity in 60% ethanol extracts but 39.9% inhibition activity in water extracts. Xanthine oxidase inhibition activity showed high inhibition activity at 73.5% in water extracts and 100% in 60% ethanol extracts. The result suggests the development of phenol compound in thyme as anti Helicobacter pylori, antioxidant and anti-gout agents.

• Magazine of the Korean Society of Agricultural Engineers
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• v.15 no.4
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• pp.3170-3180
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• 1973

This study of the subject will review past and present irrigation development in Korea. Particular attention will be given to water pricing structure and a case study on the purpose of rational operation and management of irrigation water and organizations, and the optimum irrigation water and organizations, and the optimum irrigation water fee inorder to reduce farmers burden and to rationalize the farmland associations management so as to achieve development of the rural environment. In 1971, the reservoir of the Farmland Improvement A sociation (FIA) produced only 775 millison $m^3$ of irrigation water or 77% of planned capacity of 1,015 million $m^3$. It was caused by inefficient maintenance of irrigation facilities; for instance, about 21% of reservoirs, pumping stations and weirs in Korea have been silted by soil erosion which hinder to water production according to an ADC survey. The first Irritation Association was established in 1906, whcih was renamed the Farmland Assoeiation by the Rural Development Enouragement Law in 1970. By the end of 1971, 411,000 ha of rice paddies were under the control of 267 associations nationwide. The average water price assessed by Associations nationwide rose from 790 won per 0.1 ha. in 1966 to 1,886 won in 1971. The annual growth rate was 20%. The highest water price in 1971 was 4,773 won her 0.1 ha. and the lowest was 437 won. This range was caused by differences in debt burden, geographic conditions and management efficiency among the Associations. In 1971, the number of Associations which exceeded the average water price of 1,886 won per 0.1 ha. was 144, or 55.1% of all Association. In determination of water price, there are two principles; one is determined by production cost such as installation cost of irrigation facilities, maintenance cost, management cost and depreciation ect. For instance, the Yong San River Development project was required 33.7 billion won for total construction and maintenance cost is 3.1 billion won for repayment, maintenance and management cost per year. The project produces 590 million $m^3$ of irrigation water annually. Accordingly, the water price per $m^3$ is 5.25 won. The other principle is determined by water value in the crop products and in compared with production of irrigated paddy and non-irrigated paddy. By using this method, water value in compared with paddy rice vs. upland rice(Average of 1967-1971) was 14.15 won per $m^3$ and irrigated paddy vs. non-irrigated paddy was 2.98 won per $m^3$. In contrast the irrigation fee in average association of 1967-1971 was 1.54 won per $m^3$. Accordingly, the current national average irrigation fee(water price) is resonable compared with its water value. In this study, it is found that the ceiling of water price in terms of water value is 2.98 won per $m^3$ or 2,530 won per 0.1 ha. However, in 1971 55% of the associations were above the average of nationwide irrigation fees. which shows the need for rationalization of the Association's management. In connection with rationalization of the Association's management, this study recommends the following matters. (1) Irrigation fee must be assessed according to the amount of water consumption taking intoaccount the farmer's ability. (2) Irrigation fee should be graded according to behefits and crop patterns. (3) Training personnel in the operation and procedures of water management to save O&M costs. (4) Insolvent farmland association should be integrated into larger, sound associations in the same GUN in order to reduce farmers' water cost. (5) The maintenance and repair of existing irrigation facilities is as important as expansion of facilities. (6) Establishment of a new Union of Farmland Association is required to promoted proper maintenance and to protect the huge investment in irrigation facilities by means of technical supervision and guidance.

• Applied Biological Chemistry
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• v.51 no.1
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• pp.70-78
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• 2008

Prunus sargentii R. of Rosaceae familiy, has been reported to have radical scavenging activity and anti-inflammatory effect. On these facts, biological activity and safety test were conducted to evaluate biological activities of the extracts of P. sargentii R. as a potential pharmaceutical ingredient. The electron donating ability of its ethanol extracts at a 500 ppm level showed 92%, which was higher than that of hot water extract (59%), the superoxide dismutase (SOD)-like activity of the water extract of P. sargentii R. was about 50%, the ethanol extract of P. sargentii R. was about 40% at 1,000 ppm concentration. Xanthine oxidase inhibition by the water extract of P. sargentii R. was about 40% and that by the ethanol extract was 60% respectively at 500 ppm concentration. From the measurement on lipid oxidation, the $Cu^{2+}$ chelating effect of the ethanol extract was higher than that of hot water extract. The $Fe^{2+}$ chelating effect was also shown to be about 80% at a 500 ppm concentration in both hot water extract and ethanol extract. The tyrosinase inhibition effect related to skin-whitening was 26% by hot water extract and 20% by ethanol extract respectively at a 1,000 ppm. Hyaluronidase inhibition activity related to the anti-inflammation effect was 96% in ethanolic extract at a 500 ppm. Clear zones formed by P. sargentii R. against the human skin-resident micro-flora such as Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli and Propionibacterium acnes indicated that antimicrobial activity of the ethanol extract was higher than that of the hot water extract.

• Journal of Applied Biological Chemistry
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• v.57 no.2
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• pp.145-152
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• 2014

To evaluate the improving effects of antioxidant activity, we observed antioxidant capacities such as electron donating ability (EDA), Ferric reducing antioxidant power (FRAP), inhibitory activity of xanthine oxidase (XO) and aldehyde oxidase (AO), and sensory characteristics on mixture of Smilax china L. root water extract added with water extract of fermented S. china L. leaf by Aspergillus oryzae (FSCL). Those contents of mixture with higher ratio of FSCL were proportionally high. And OD475 of mixture with higher ratio of FSCL was almost proportionally high ($R^2=0.9850$). Antioxidant capacities of EDA and FRAP of the mixture was higher than that of non-mixture. In addition, XO inhibitory activity ($IC_{50}$) of A (1.19) was 59.80% higher than that of F (2.96), and the activity of mixture by the higher ratio of FSCL was proportionally low ($R^2=0.9490$). Taste acceptability of A was slightly higher than that of F, whereas that of C was highest. And color acceptability of 40-80% mixture was higher than those of A, F, and B. Overall acceptability of C and D was highest than those of others. Moreover, hot water extract of S. china L. leaf fermented with A. oryzae was maroon color, which looks like Puerh tea style, and mixture of S. china L. root extract added with hot water extract of S. china L. leaf was high acceptability of beverage. These results suggest that mixture of extract of S. china L. root and hot water extract of S. china L. leaf fermented with A. oryzae could improve antioxidant activities.

• Microbiology and Biotechnology Letters
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• v.3 no.3
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• pp.123-134
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• 1975

Out of 96 yeast strains isolated from various natural habitats, five strains were screened based on their ability to ferment agricultural biproducts such as rice-, barley-and wheat-bran, and sawdust. These were identified as Hansenula anomala var anomala, Candide utilis, C. pelliculosa, Debaryomyces hansenii, and Irpex lacteus. Using these yeasts the above mentioned agricultural biproducts were fermented in various combinations. The fermented product was fed to 180 male Starcroses for eight weeks and obtained a body weight increase of 15.1g a day, while the unfermented control feed increased 10.5g a day.

• Journal of Intelligence and Information Systems
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• v.21 no.1
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• pp.29-45
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• 2015

Response modeling is a well-known research issue for those who have tried to get more superior performance in the capability of predicting the customers' response for the marketing promotion. The response model for customers would reduce the marketing cost by identifying prospective customers from very large customer database and predicting the purchasing intention of the selected customers while the promotion which is derived from an undifferentiated marketing strategy results in unnecessary cost. In addition, the big data environment has accelerated developing the response model with data mining techniques such as CBR, neural networks and support vector machines. And CBR is one of the most major tools in business because it is known as simple and robust to apply to the response model. However, CBR is an attractive data mining technique for data mining applications in business even though it hasn't shown high performance compared to other machine learning techniques. Thus many studies have tried to improve CBR and utilized in business data mining with the enhanced algorithms or the support of other techniques such as genetic algorithm, decision tree and AHP (Analytic Process Hierarchy). Ahn and Kim(2008) utilized logit, neural networks, CBR to predict that which customers would purchase the items promoted by marketing department and tried to optimized the number of k for k-nearest neighbor with genetic algorithm for the purpose of improving the performance of the integrated model. Hong and Park(2009) noted that the integrated approach with CBR for logit, neural networks, and Support Vector Machine (SVM) showed more improved prediction ability for response of customers to marketing promotion than each data mining models such as logit, neural networks, and SVM. This paper presented an approach to predict customers' response of marketing promotion with Case Based Reasoning. The proposed model was developed by applying different weights to each feature. We deployed logit model with a database including the promotion and the purchasing data of bath soap. After that, the coefficients were used to give different weights of CBR. We analyzed the performance of proposed weighted CBR based model compared to neural networks and pure CBR based model empirically and found that the proposed weighted CBR based model showed more superior performance than pure CBR model. Imbalanced data is a common problem to build data mining model to classify a class with real data such as bankruptcy prediction, intrusion detection, fraud detection, churn management, and response modeling. Imbalanced data means that the number of instance in one class is remarkably small or large compared to the number of instance in other classes. The classification model such as response modeling has a lot of trouble to recognize the pattern from data through learning because the model tends to ignore a small number of classes while classifying a large number of classes correctly. To resolve the problem caused from imbalanced data distribution, sampling method is one of the most representative approach. The sampling method could be categorized to under sampling and over sampling. However, CBR is not sensitive to data distribution because it doesn't learn from data unlike machine learning algorithm. In this study, we investigated the robustness of our proposed model while changing the ratio of response customers and nonresponse customers to the promotion program because the response customers for the suggested promotion is always a small part of nonresponse customers in the real world. We simulated the proposed model 100 times to validate the robustness with different ratio of response customers to response customers under the imbalanced data distribution. Finally, we found that our proposed CBR based model showed superior performance than compared models under the imbalanced data sets. Our study is expected to improve the performance of response model for the promotion program with CBR under imbalanced data distribution in the real world.