• Journal of radiological science and technology
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• v.37 no.3
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• pp.233-238
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• 2014

The amount of environmental radiation was measured in the indoor(basement) and outdoor(rooftop) of the two buildings of the University (the old building and the new building) in Suwon City, Gyeonggi Province. Measuring the environmental radiation dose from the first week of April 2013 to last week of March 2014, Twice a week, one year. The measured results were as follows. 1. The average annual environmental radiation of the two buildings were $0.169727{\mu}Sv/hr$. The lowest value was $0.0760{\mu}Sv/hr$ whereas the highest value was $0.3000{\mu}Sv/hr$. 2. The amount of environmental radiation dose was $0.176373999{\mu}Sv/hr$ in the old building and the amount of environmental radiation dose was $0.163052885{\mu}Sv/hr$ in the new building. The old building environmental radiation dose was higher then the new building. 3. The month of the lowest amount of environmental radiation dose in a year was November resulting in $0.152844{\mu}Sv/hr$ whereas May was found the month of the highest amount of environmental radiation dose showing with $0.197222{\mu}Sv/hr$. 4. The amount of environmental radiation dose in the indoor(basement) was $0.164649{\mu}Sv/hr$ and the amount of environmental radiation dose of the outdoor(rooftop) was $0.174779{\mu}Sv/hr$. And the outdoor(rooftop) was higher than the indoor(basement). 5. Depending on seasonal, the lowest amount of environmental radiation dose was in winter with $0.1632{\mu}Sv/hr$ while spring was the season with the highest amount of environmental radiation dose with $0.183846{\mu}Sv/hr$. The measured amount was high in the order of spring, summer, autumn, and winter.

• Korean Journal of Plant Resources
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• v.29 no.2
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• pp.241-263
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• 2016

This study was carried out to survey the vascular plants on Mt. Seokbyeongsan (1,055 m) and provide a basis for the conservation and management of plant resources. The vascular plants were surveyed from March to October 2015. The flora on Mt. Seokbyeongsan was classified as follows: 102 families, 295 genera, 454 species, 4 subspecies, 51 varieties, 7 forms, and a total of 516 taxa. Endemic plants included 17 families, 24 genera, 25 species, 1 variety, and a total of 26 taxa. The Korea Forest Service assignment of rare plants, including 21 families, 33 genera, 33 species, 3 varieties, and a total of 36 taxa, was investigated. Moreover, the Ministry of Environment assignment of rare plants, including 13 families, 17 genera, 17 species, 1 variety, and a total of 18 taxa, was investigated. Floristic special plants in the surveyed area were divided into five classes (Classes I-V): 42 taxa of Class I, 26 taxa of Class II, 35 taxa of Class III, 20 taxa of Class IV, and 9 taxa of Class V for a total of 132 taxa. Naturalized plants were 18 taxa, and plants threatened by climate change were 48 taxa.

• Journal of the Korean Association of Geographic Information Studies
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• v.23 no.2
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• pp.1-20
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• 2020

The purpose of this study was to analyze the distribution characteristics of spatial and temporal PM_2.5 in urban areas of Changwon-si, and to identify the causes of PM_2.5 by comparing the characteristics of land-use, and to suggest the direction of reduction measures. As the basic data, the every hour average from September 2017 to August 2018 of Airpro data, which has measurement points in kindergartens, elementary schools, and some middle and high schools in Changwon-si was used. Also, by using IDW method among spatial interpolation methods of GIS, monthly and time-slot distribution maps were constructed, and based on this, spatial and temporal PM_2.5 distribution characteristics were confirmed. First, to verify the accuracy of the Airpro data, the correlation with AirKorea data managed by the Ministry of Environment was confirmed. As a result of the analysis, R² was 0.75~0.86, showing a very high correlation and the data was judged that it was suitable for the study. In the monthly analysis, January was the highest year, and August was the lowest. As a result of analysis by time-slot, The clock-in time at 06-09 was the highest, and the activity time at 09-18 was the lowest. By administrative district, Sangnam-dong, Happo-dong, and Myeonggok-dong were the most severe regions of PM_2.5 and Hoeseong-dong was the lowest. As a result of analyzing the land-use characteristics by administrative area, it was confirmed that the ratio of traffic area and commercial area is high in the serious area of PM_2.5. In conclusion, the results of this study will be used as basic data to grasp the characteristics of PM_2.5 distribution in Changwon-si. Also, it is thought that the severe regions and the direction of establishing reduction measures derived from this study can be used to prepare more effective policies than before.

• Korean Journal of Agricultural Science
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• v.2 no.2
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• pp.381-398
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• 1975

Present work was executed to evaluate effects of adjuvants. stabilizers. moisture. pH and heavy metals on the stability of Fenitrothion in the emulsifiable concentrate. In addition, susceptibility ' of Fenitrothion in various formulations, to UV-irradiation has been also examined. The results are summarized as follows; 1. Xylene and benzene were found to be satisfactory solvents for Fenitrothion emulsifiable concentrate. As expected, polar sol vents such as aliphatic alcohols considerably reduced stability of the pesticides. 2. Of the two non-ionic emulsifiers, an alkyl aryl type Sorpol-1200, in contrast to sorbitan type Tweens, substantially reduced decomposition of Fenitrothion in the emulsifiable concentrates. Moisture and pH of emulsifiers. in the ranges studied. affected little if any. on the stabi ity of the Fenitrothion during the experiment periods. 3. Maleic anhydride, p-toluene sulfonic acid, sulfosalicylic acid, maleic anhydride-sulfosalicylic acid reduced decomposition of Fenitrothion in the emulsifiable concentrate. Addition of organic acids, however, increased liability of Fenitrothion in the emulsifiable concentrate. 4. Presence of either zinc or copper metals in the emulsifiable concentrate containing Tween-80 as a emulsifier, reduced stability of the Fenitrothion. 5. UV-irradiation, as expected, brought decomposition of Fenitrothion. The liability of Fenitrothion formulations decreased in the order, wettable powder ${\gg}$ dust > emulsifiable concentrate.

• Journal of Korean Academy of Nursing Administration
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• v.5 no.1
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• pp.149-167
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• 1999

This study was designed and carried out to investigate the effect of Assertiveness Training on the stress response and assertive behavior of emergency room nurses from September 22, to December 21. 1997. The subjects were 45 emergency room nurses of three general hospitals of Korea University Medical Center; 25 assigned for the experimental and 20 for the control group. The Assertive Training Program was composed of cognitive training, behavioral training and progressive muscle relaxation. The subjects of the experimental group carried out the 15-minute progressive muscle relaxation according to recorded-tape once a day for 6 weeks. The cognitive and the behavioural training were conducted by the investigator for 5-8 subjects at a time for 9 series, at an interval of 4-5 days. Post-measurement were administered to all sujects in two groups three weeks after the last session. The level of general stress (Cline, 1992), job stress (Kim & Koo, 1984), physiological response to stress (cortisol, epinephrine, norepinephrine), symptoms of stress (Lee, 1984) and assertive behavior (Kim, 1982) were measured before the first and after the last experiments. Data were analysed by x2, t, paired t, Wilcoxon signed rank tests Wilcoxon rank sums tests. The results are as follows : 1. The level of general stress of the experimental group was lower than that of the control group, however, no significant difference between the two groups (P=0.234) was revealed. 2. A significant reduction of job stress was revealed in the experimental group (P=0.017). 1) A significant reduction of interpersonal conflicts in the experimental group was revealed (P=0.018). 3. The physiological stress-response were analyzed as follows : 1) A decrease of Cortisol in both the experimental and the control groups was noticed, however, the difference between the two groups was not statistically significant (P=0.991). Pre-and post-measurement of the level of Corti sol revealed that a notable decrease in the experimental group and an increase in the control group with no significant difference in the day-day subjects (P=0.765), a significant decrease was noted on the level of Cortisol of the experimental group in the night-night nurses (P=0.036). 2) An increase of Epinephrine in both groups was noticed, however, a difference was not statistically significant between the two groups (P=0.082). Pre-and post-measurement of the level of Epinephrine revealed that a notable decrease in the experimental group and an increase in the control group with no significant difference in the day-day subjects (P=0.136). increases were noted on the level of Epinephrinel of both groups in the night-night nurses (P=0.136), 3) The level of Norepinephrine of the experimental group was significantly decreased (P=0.020). Pre-and post-measurement of the level of Norepinephrine revealed that a notable decrease in the experimental group and an increase in the control group with no significant difference in the day-day subjects (P=0.073). a significant decrease was noted on the level of Norepinephrine of the experimental group in the night-night nurses (P=0.036), 4. Symptoms of stress were reduced in both groups, with no significant differences between the groups (P=0.127). 1) The physical stress symptoms were reduced in both groups, with no significant difference (P=0.386), 2) The cognitive-behavioral stress symptoms were significantly reduced in the experimental group (P=0.037). 3) The emotional stress symptoms were reduced in both groups with no significant difference between the groups (P=0.110). 5. The assertive behavior was significantly increased in the experimental group (P=0.000). This study signified the Assertiveness Training as an effective mean of self intervention for the reduction of stress of nurses assigned to emergency rooms.

• Journal of the Korean Institute of Landscape Architecture
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• v.47 no.6
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• pp.115-128
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• 2019

Huam-dong is a representative area from the Japanese colonial period and is the space where most Japanese-style buildings remain in Seoul. Interest in modern cultural heritage continues to increase, including the registration of cultural properties in 2001, building assets in 2015, and the registration of cultural property units in 2018. As the debate continues over the necessity of preserving cultural heritage that reminds us of the Japanese colonial, there is a need for research to grasp the perceptions of stakeholders along with the perceived value of such spaces. This study identified the subjective perception types of the stakeholders concerned with the Japanese-style building group in Huam-dong, analyzed characteristics by types, and debated the issues. For this purpose, Q methodology, which is a statistical technique for measuring human self-subjectivity and extracting common human perspectives, was used. A literature study on the values of Huam-dong and modern cultural heritage was conducted, and a Q questionnaire based on five aspects of modern cultural heritage values (historical, architectural, sociocultural, landscape, and economic) was applied. The results of the study depicted three types of cognition and showed different attitudes toward the Japanese building group. This study found a conflict comparing the perceptional differences between the types of cognition. This study is meaningful in that it provides an in-depth approach to the perspectives of the stakeholders concerned with the Japanese-style buildings clustered in central Seoul. It is also meant to present a theoretical framework that can be applied to the use area as sustainable cultural heritage through the establishment of preservation and utilization of Japanese-style areas and conflict resolution.

• Korean Chemical Engineering Research
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• v.51 no.1
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• pp.111-115
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• 2013

The optimum synthetic conditions of poly(p-phenylphenol) by horseradish peroxidase in dioxane:water (80:20 v/v) mixtures were studied. The stability against thermal degradation and structural properties of the synthesized phenolic resins were investigated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), respectively. The synthetic yield of poly(p-phenylphenol) increased upon the increase of the amount of enzyme up to 0.25 mg HRP/mL, then leveled off for further increase of the enzyme usage. When sodium acetate (100 mM, pH 4~6) and sodium phosphate (100 mM, pH 7~9) were used as the buffering salts for the aqueous component (20% v/v), the synthetic yield of the resin increased at higher pH of the aqueous buffer. But when the pHs of the aqueous buffer were 6 and 9, the synthetic yield strongly depended on the types of the buffering salts; if sodium phosphate was used instead of sodium acetate at pH 6, the yield decreased by about 15% and if sodium bicarbonate was used instead of sodium phosphate, the yield decreased by almost 20%. When the pH range of the aqueous buffer was from 4 to 7, the addition of a radical mediator, 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonate) (ABTS), up to 2 mM improved the synthetic yield of the resin by about 10%. TGA experiments revealed that the thermal stability of the resin synthesized in dioxane:water (100 mM sodium phosphate, pH 9) (80:20 v/v) was high having the char yield of 47% upon the heating at $800^{\circ}C$. DCS results showed that the structures of the polymers synthesized in acidic aqueous buffers were different from those of the polymers synthesized in the basic aqueous buffers. However, all the synthesized resins were found to have the property of the thermosetting resins.

• Journal of the Korean Ceramic Society
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• v.34 no.2
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• pp.145-156
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• 1997

ZrO2 phase transformations depending on the type and amount of dopants and the sintering temperatures were studied for the 2 components (CaO-, Y2O3-, MgO-ZrO2) and the 3 components(MgO-ZrO2-Al2O3)ZrO2 powder by X-ray diffraction and Raman spectroscopy. In the CaO- and Y2O3-ZrO2 systems, as the CaO and Y2O3 contents increased to 6~15mol% and 3~15mol% respectively, we were not able to identify between tetragonal and cubic in the X-ray diffraction patterns. On the other hand, all Raman modes shifted to lower wavenumbers, decreasing in intensity and the number of bands, markedly. These phenomena were caused by tetragonallongrightarrowcubic phase transformation and interpreted by the breakdown of the wave vector selection rule(k=0) and the structural disorder associated with the formation of oxygen sublattice which was caused by the substitution between Zr4+ ion and Ca2+ or Y3+ ion in ZrO2 matrix. The monoclinic to cubic phase transformation occurred in 10mol% MgO-ZrO2 system. As the Al2O3 content increased from 0 to 20mol% in the MgO-ZrO2-Al2O3 systems, cubic phase transformed to monoclinic phase, this is because the MgO didn't play a role in a stabilizer because of the formation of the spinel(MgAl2O4) by the reaction between MgO and Al2O3, Also, the ZrO2 phase transformation was explained by the change of it's lattice parameters depending on the type and amount of dopants. Namely, as the amount of dopant increased to 10~13mol%, the axial ra-tio c/a came close to unity with increasing the lattice parameter a and decreasing the lattice parameter c. At that time, the tetragonallongrightarrowcubic phase transformation occurred.

• KDI Journal of Economic Policy
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• v.32 no.1
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• pp.131-169
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• 2010

I develop a matching model in which risk-averse workers face borrowing constraints and make a labor force participation decision as well as a job search decision. A sharp distinction between unemployment and out of the labor force is made: those who look for work for a certain period but find no job are classified as the unemployed and those who do not look for work are classified as those out of the labor force. In the model, the job search decision consists of two steps. First, each individual who is not working obtains information about employment opportunities. Second, each individual who decides to search has to take costly actions to find a job. Since individuals differ with respect to asset holdings, they have different reservation job-finding probabilities at which an individual is indifferent between searching and not searching. Individuals, who have large asset holdings and thereby are less likely to participate in the labor market, have high reservation job-finding probability, and they are less likely to search if they have less quality of information. In other words, if individuals with large asset holdings search for job, they must have very high quality of information and face very high actual job-finding probability. On the other hand, individuals with small asset holdings have low reservation job-finding probability and they are likely to search for less quality of information. They face very low actual job-finding probability and seem to remain unemployed for a long time. Therefore, differences in the quality of information explain heterogeneous job search decisions among individuals as well as higher job finding probability for those who reenter the labor market than for those who remain in the labor force. The effect of the extended maximum duration of unemployment insurance benefits on the aggregate labor market and the labor market flows is investigated. The benchmark benefit duration is set to three months. As maximum benefit duration is extended up to six months, the employment-population ratio decreases while the unemployment rate increases because individuals who are eligible for benefits have strong incentives to remain unemployed and decide to search even if they obtain less quality of information, which leads to low job-finding probability and then high unemployment rate. Then, the vacancy-unemployment ratio decreases and, in turn, the job-finding probability for both the unemployed and those out of the labor force decrease. Finally, the outflow from nonparticipation decreases with benefit duration because the equilibrium job-finding probability decreases. As the job-finding probability decreases, those who are out of the labor force are less likely to search for the same quality of information. I also consider the matching model with two states of employment and unemployment. Compared to the results of the two-state model, the simulated effects of changes in benefit duration on the aggregate labor market and the labor market flows are quite large and significant.

• The Journal of Korean Academy of Prosthodontics
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• v.53 no.3
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• pp.189-197
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• 2015

Purpose: The aim of this study was to assess the degree of awareness and actual practice of dental practitioners regarding infection control during prosthodontic treatment. Materials and methods: Study participants were composed of dentists, dental hygienists, dental technicians working at dental university hospital, general hospital, dental hospital and dental clinics in Daejeon, Korea (n=126). The questionnaires included the data on general characteristics, education, awareness and practice of infection control procedures during prosthodontic treatment through personal self-administration survey. Awareness and practice were measured by Likert scale ranging from 1 to 5. Statistical analysis was done by one-way ANOVA. Influence of awareness on practice was estimated by regression analysis. Results: 27.7% of the respondents answered that the infection control education regarding prosthodontic treatment is insufficient. The mean value of awareness and practice of infection control during the prosthodontic treatment were $2.72{\pm}0.80$, $1.58{\pm}0.88$, respectively. The mean value of practice who answered that had education curriculum at college was $1.62{\pm}0.9$, and $1.31{\pm}0.49$ who did not. The mean value of awareness who equipped guideline was $3.01{\pm}0.9$, and $2.56{\pm}0.70$ who did not. Conclusion: 1. The respondents who received the infection control education by college curriculum showed higher degree of practice than the respondents who did not. 2. The respondents who have appropriate infection control guidebook in their workplace showed higher degree of awareness than the respondents who did not. 3. There was a correlation between the awareness and practice of infection control during prosthodontic treatment; the degree of awareness becomes higher, so does the degree of practice. 4. During the prosthodontic treatment, the degree of practice was lower than the degree of awareness on infection control.