• Korean Journal of Materials Research
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• v.3 no.5
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• pp.553-561
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• 1993

In this study, thr effect of $Bi_2O_3$ and BN addition as grain boundary modifiers on sintering and electrical properties of semiconducting PTCR(Positive Temperature Coefficient of Resistivity) mate rial were analyzed using TMA, XRD and Complex Impedance Spectroscopy method. Bismut.h Ox~de and Boron Nitride were added to Y-doped $BaTiO_3$ respectively. Bismuth sesquioxide up to O.lmol%solubil~ ty limit of $Bi_2O_3$ in Y--$BaTiO_3$ ceramics-retarded densification and grain growth, and further addition mitigated these retardation effects. The resistivity at room temperature increased with increasing amount of $Bi_2O_3$ and thus decreased the PTCR effect, probably due to the $Bi_2O_3$ segregation on the grain boundaries. From the complex ~mpedance pattern, it is known that the grain boundary resisitivity is dominant on the whole resistivity of sample. In the result of applying the defect chemistry, $Bi^{3+} \;and \; Bi^[5+}$ are substituted for Ua and Ti site, respectively. Boron nitride decomposed and formed liquid phase among the $BaTiO_3$ grains. The decomposed com~ ponents made the second phase and existed the tr~ple juntion from the result of EPMA. From the complex impendencc pattern, the gram and grain boundary resistivity were small. The grain size increased with increasing BN contents, and decreased grain boundary resistivity enhanced the PTCR effect.

• Korean journal of applied entomology
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• v.31 no.4
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• pp.386-395
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• 1992

The black pine bast scale, Matsucoccus thunbergianae, causes severe damage to the black pines of southern coastal areas. It has one generation a year, coming out of the pine bark to mate a and lay eggs from early March to early May. Especially, its peak time is from late March to m mid-April. The host plants were found to be 7 species, Pinus thunbergii, P. strobus, P. taeda, P. b banksiana, P. massoniana, P. taiwannesis, and P. densiflora. The percentage of damaged black p pine by the age were 0.8% for I-year old ones, 3.7% for 4-6 years, 5.2% for 7-9 years, 9.3% f for 10-12 years, 8.1% for 13-15 years, 7.8% for 16-18 years, 6.7% for 19-21 years, 3.3% for 2 22-24 years, 1.9% for 25-27 years, and 1.1 % for 28 years. The highest rate of damage happened to 7 -20 years old trees, whereas the highest rate of damage upon branches happened to 6 6-7 years old ones. Finally, as far as the trunk is concerned, the damages proceeded from the m middle parts of the trunk, whose branches were alive up to the top. The rates of damage s spread in pure forest/mixed forest area were turned out to be 81.3/52.5% in Koheung, 80.3/ 5 58.1 % in Haenam, and 76.3/48.5% in Muan. That is, the damage rate was higher in the pure f forest areas than the mixed forest ones. The higher the density of trees beyond 20 trees per m 100$m^2$, the higher the damage rate was.

• Journal of the Korea Society of Computer and Information
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• v.16 no.3
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• pp.45-51
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• 2011

This paper proposes a method to accelerate the evolution speed of individuals through hybrid reproduction of monogenesis and gamogenesis. Monogenesis as a reproduction method that bacteria or monad without sexual distinction divide into two individuals has an advantage for local search and gamogenesis as a reproduction method that individuals with sexual distinction mate and breed the offsprings has an advantages for keeping the diversity of individuals. These properties can be properly used for improvement of evolution speed of individuals in genetic algorithms. In this paper, we made relatively good individuals among selected parents to do monogenesis for local search and forced relatively bad individuals among selected parents to do gamogenesis for global search by increasing the diversity of chromosomes. The mutation probability for monogenesis was set to a lower value than that of original genetic algorithm for local search and the mutation probability for gamogenesis was set to a higher value than that of original genetic algorithm for global search. Experimental results with four function optimization problems showed that the performances of three functions were very good, but the performances of fourth function with distributed global optima were not good. This was because distributed global optima prevented individuals from steady evolution.

• The Journal of Korean Physical Therapy
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• v.3 no.1
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• pp.39-58
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• 1991

This study was carried out to recognize the understanding of high school teachers about physical therapist during September in 1988, The study population was comprised of 511 high school teachers who had lived in Seoul and Kyunggi Province. Mate teachers were $56\%$ and the rest of them were females. In age distribution $45.4\%$ of them belonged to the 3rd decade, in religion $36.2\%$ of them were Christians, and in their carrier $45.8\%$ of them were less then 5 years. The results obtained were as follows. 1. The high school teachers who knew about department of physical therapy is amounted to $62.6\%$ in male and $49.8\%$ in female. The high school teachers ($41.7\%$ in male and $38.6\%$ in female) considered that students aptitude was the most important thing to keep in mind in counselling those who wished to become physical therapists. There were difference in opinion between male and female teachers as to the counselling criteria (p<0.05). 2. The high school teachers who knew that the students would beemployed in sport center and health clubs after graduation amounted to $24.3\%$ in males and in general hospital to $27.1\%$ in female. There was significant difference in the knowledge for their field of employment between male and female teachers (p<0.05). 3. As to the effectiveness of the physical therapy, $41.3\%$ of male and $29.8\%$ of the female teachers responded to 'satisfactory', but indicating no statistical difference both sexes. 4. As for the attitude of physical therapiest, $43\%$ of them answered that kindness and service devotion were the prerequisite for them. There were statistical difference between male and female teachers in concepts about attitude (p<0.05). To the social level of physical therapist, majority of the teachers thought that physical therapist belong to moderate level in social class. 5. Those who considered that the physical therapy was necessary means for treatment of trauma amounted to $73\%$. The reason why teachers thought that physical therapy was not necessary was that it required too long period of time for the treatment. 6. Those who knew fully the job of physical therapist amounted to $55\%$ and the 55. $9\%$ knew that physical therapists work only at hospitals as the therapist and the rest of them misunderstood the job of physical therapist. 7. As for the academic background to be qualified as physical therapist, $76.2\%$ of them said that graduation of Junior College was required, $12.9\%$ graduation of Senior College and the rest of them had no ideas at all. There was no statistical difference between male and female teachers.

• Journal of Food Hygiene and Safety
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• v.17 no.2
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• pp.101-105
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• 2002

A total of 53 vegetables and fruits, consisting of 23 leaf vegetables, 4 fruits vegetables, 4 edible roots,7 spice vegetables and 15 fruits were analyzed for contents of nitrate and nitrite by ion chromatography. Nitrite was detected 10 of 23 kinds of leaf vegetables, which was dominant in lettuce by average 349.9 mg/kg. Nitrate contents of leaf vegetables were average 578.3 mg/kg, 415.7 mg/kg, 348.6 mg/kg in wild plant, mustard leaf and chinese vegetable, respectively. Nitrite was not detected in fruits vegetables and rootcrops but the nitrate contents were abundant and the highest in squash(average, 86.2 mg/kg) and radish(average, 297.5 mg/kg), respectively. In spice vegetables, mate contents were from 0 to 29.8 mg/kg, but not detected in garlic. In welsh onion, its nitrite were higher in small type than large type, while nitrate contents were higher 3 times in the latter. Nitrate contents of fruits were lower in apple(average, 0.5 mg/kg) and higher in plum(average, 76.6 mg/kg) than other samples.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.4
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• pp.500-507
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• 1998

Using a sledge net, the benthic amphipods were taken over one cycle of the neap and spring tides in January 1993 at the sandy shore surf zone of Dolsando, southern Korea. From these samples, we investigated the diel and tidal effects on the intraspecific zonation of Pontogeneia rostrata. The density of p. rostrata was higher during neap tide than spring. Of three categories (adult males and females and juveniles), juveniles and males attained to its highest density during neap and spring tides, respectively. Length- frequency data show that the high mortality of juveniles seemed to occur in winter. In the surface at night, it is significant that juveniles were significantly more abundant during neap tide than spring, whereas both adult males and females were more abundant during spring tide than neap. This suggests that the vortical migration patterns of juveniles and adults vary with the type of tides. During flood of spring tide, more than $90\%$ of population collected at the area above the mean sea level (MSL) were adults. With a decrease of female/male ratio, size of males increased there but that of female did not change, indicating an active migration of large males. This behavior can provide an extension of distribution area far large males, and also give a competitive advantage to large male against small one for mate and feeding. Although adult p. rostrata was collected at 100 cm above MSL at night during spring tide, a major portion of population as usually present on the shore below MSL. The center of zonation was restricted from 50 cm to 250 cm below MSL.

• Journal of Environmental Health Sciences
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• v.45 no.4
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• pp.370-380
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• 2019

Objective: This study was performed to investigate the distribution of individual exposure characteristics according to an exposure assessment classification for humidifier disinfectant and to identify the factors that influence assessment classification. Methods: We examined the exposure characteristics of 4,482 subjects who applied for the 4-1 and 4-2 assessments of environmental exposure to humidifier disinfectant conducted by the Korea Environmental Industry & Technology Institute (KEITI). Environmental exposure assessment classification was assessed using the following seven criteria: 1) Distance from humidifier to face; 2) Spray direction; 3) Time used, daytime 4) Time used, during sleep; 5) Time used, cumulative; 6) Exposure intensity; and 7) Cumulative exposure level. Each criteria was then classified as 'high' or low'. When participants answered for more than four criteria, exposure assessment was determined as 'definite,' 'probable,' or 'possible' depending on the ratio of 'high' responses. If participants' responses were inconsistent, exposure assessment was listed as 'unlikely.' If participants answered for less than four criteria, exposure assessment was considered 'indeterminate.' Results: For the exposure assessment classes, definite was assigned to 38.5% (1,725 subjects), probable assigned to 32.9% (1,474 subjects), 25.0% (1,122 subjects) were assigned to as possible, unlikely assigned to 0.1% (3 subjects), and indeterminate assigned to 3.5% (158 subjects). Overall, participants who used 'Oxy Ssakssak New Gaseupgi Dangbun,' 'Aekyung Gaseupgi Mate,' 'Homeplus Gaseupgi Chungjungje,' and 'E-Mart Gaseupgi Salgyunje' totaled 2,996, 557, 176, and 162 subjects, respectively. There was a statistical difference in the type of humidifier disinfectant products between high-exposed and low-exposed participants. Based on the assessment criteria of humidifier disinfectant exposure, subjects were likely to be in the highly exposed classes (definite and probable) when the subjects were exposed 1) for more than ten hours per day and 2) for more than four hours at night 3) when the total cumulative exposure time was higher than the average, 4) when the direction of humidifier spray was toward the face, 5) when the respiratory position was less than 1 meter of distance from the humidifier, 6) when the concentration of indoor contaminants (ug/m3) was higher than the average exposure intensity, and 7) when overall exposure level ($ug/m3^*hr$) was higher than the average exposure level. Conclusion: This study suggests that each exposure assessment criteria was able to appropriately estimate cumulative exposure levels.

• Journal of the Korea Society of Computer and Information
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• v.26 no.2
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• pp.141-150
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• 2021

Article 117, Paragraph 1 of the 「Constitution」 states that "Local governments may enact provisions relating to local autonomy, within the limit of Acts and subordinate statutes". It restricts the enactment of effective self-government laws. The fundamental problem-solving is securing the right to self-governing legislation through constitutional amendment. Therefore, it must be revised to "Local governments can make regulations on self-government to the extent that they handle resident welfare affairs in accordance with the subsidiarity and do not violate the law." In the long-term perspective, the current education council problem, which is contrary to the constitution, has to be revived as a constitutional independent education committee system, and the voting agency and the executive agency must go together and education councilors must have about 10 years of experience in education and education administration. The current superintendent's election system is of great significance in establishing democratic legitimacy by ensuring residents' right to vote and securing a superintendent's representation of residents. It hasn't been long since the system was implemented, but there are some side effects and it is argued that the election system should be replaced by the appointment by the head of the local government, the running mate system or the joint registration system. However it is thought that it is necessary to minimize and supplement the side effects rather than fixing the system as it violates the Constitution of the local education autonomy system.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.21 no.1
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• pp.43-51
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• 1976

Marine deposite soil was studied to evaluate morohological changes of paddy rice under subdrainage control. The content of organic and inorganic mate rial were low at high temperature in the mid-summer. This soil lacked air and accumulated more H$_2$ S. Thus rice root was rotted with high infection of virus and insect and yield was relatively low.

• Journal of Pharmacopuncture
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• v.26 no.4
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• pp.338-347
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• 2023

Objectives: Ilex paraguariensis (Aquifoleaceae) is cultivated to produce "yerba mate". Due to its nutritional, energizing, hypoglycemic and antioxidant effects, it is used in the elaboration of food, pharmaceuticals, and cosmetics. The oxidative stress related to protein glycation and production of advanced glycation end products (AGEs) leads to the development of several diseases. The objective of this work was to compare the antioxidant and anti-AGEs activity of a decoction of fruits (F) and leaves (L). Methods: The antioxidant activity was assayed by the DPPH assay and the inhibition of egg yolk lipid peroxidation (ILP), and anti-AGEs activity, through the inhibition of the formation of fructosamine (IF), β-amyloid (Iβ), protein carbonylation (IC) and AGEs (IA). Polyphenols were quantified by HPLC. Results: Maximum response ± SEM: For F 0.01 ㎍/mL: IF = 42 ± 4%, IC = 17 ± 2% and for 10 ㎍/mL: IA = 38 ± 4%, Iβ = 67 ± 7%. For L 0.1 ㎍/mL: IF = 35 ± 2%, IC = 19 ± 2% and for 100 ㎍/mL: IA = 26 ± 3%, Iβ = 63.04 ± 2%. The DPPH IC₅₀ = 134.8 ± 14 ㎍/mL for F and 34.67 ± 3 ㎍/mL for L. The ILP IC₅₀ = 512.86 ± 50 ㎍/mL for F and 154.8 ± 15 ㎍/mL for L. By HPLC L presented the highest amounts of flavonoids and caffeoylquinic acids. F and L showed strong anti-AGEs activity, affecting the early stages of glycation at low concentrations and the late stages of glycation at high concentrations. The highest activity for both F and L was seen in the IF and Iβ. F presented the highest anti-AGEs potency. L presented the highest antioxidant potency, which was related to the highest content of polyphenols. Conclusion: The fruits of I. paraguariensis could be a source of antioxidant and anti-AGEs compounds to be used with medicinal purposes or as functional food.