• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
• /
• 제1권2호
• /
• pp.81-86
• /
• 1997

The amounts of ascorbic acid in chloroplasts treated with light and light+paraquat (PQ) were reduced by 81 and $82\%$ of initial level, respectively at 24 hr at incubation. And those treated with dark and dark+PQ were decreased by 46 and $55\%$ of the original level, respectively. Malondialdehyde (MDA) contents at 24 hr of dark and dark+PQ treatment were increased by 6 and $31\%$ of the initial level, respectively. When chloroplasts were treated with light and light+PQ, MDA contents after 24 hr were increased by 88 and $146\%$ of the initial level, respectively. SOD activities treated with light and light+PQ were increased by 10 and $20\%$ of the initial level, respectively for 3 hr and thereafter reduced by 46 and $49\%$ of the original level, respectively at 24 hr. However, the SOD activities treated with dark and dark+PQ were decreased by 37 and $30\%$ of the initial level, respectively, It is considered that PQ triggers the oxidation of ascorbic acid, the induction of lipid peroxidation and the inactivation of SOD under light so that PQ has inhibitory effect on the pathway of plant metabolism.

• Journal of Oral Medicine and Pain
• /
• 제17권1호
• /
• pp.19-29
• /
• 1992

Fear at the dental treatment is a problem not only for patient but for dentist as well, because the anxious patient often require more item, even for simple procedures. The anxiety level in response to dental procedures was evaluated through a simple questionnaire, Corahs, DAS. 783 female and 790 male outpatients were studied at the Dept. of Oral Diagnosis, PNUH from 1988 to 1989. The obtained results were as follows : 1. The anxiety level in female was significantly higher than that in male, and patients in 10s and 30s showed more anxious than those in other groups. 2. Housewives and pupils revealed higher level of anxiety. 3. The anxiety level in 524 (ICD) was the highest in all diseases, inspite of no difference among various diseases. 4. There was significantly higher level of anxiety in the patient of Orthodontics and Pedodontics than those of other departments. 5. There was no difference in anxiety level between acute and chronic group. 6. Dental phobes were more in female than in male.

• Journal of Power Electronics
• /
• 제16권6호
• /
• pp.2162-2172
• /
• 2016

This paper presents a Direct Torque Control (DTC) strategy for the five-phase induction motor driven by a three-level five-phase inverter in order to improve the performance of the five-phase induction motor. In the proposed DTC technique, only 22 voltage vectors out of 243 available voltage vectors in a three-level five-phase inverter are selected and are divided in 10 sectors each with a width of $36^{\circ}$. The four different DTC combinations (DTC-I, II, III and IV) for a three-level five-phase induction motor drive are investigated for improving the performance of five-phase induction motor. All four of the DTC strategies utilize a combination of the same large and zero voltage vectors, but with different medium voltage vectors. Out of these four techniques, DTC-II gives the best performance when compared to the others. This DTC-II technique is analyzed in detail for improvements in the performance of five-phase induction motor in terms of torque ripple, x-y stator flux and Total Harmonics Distortion (THD) of the stator phase current when compared to its two-level counterparts. To verify the effectiveness of the proposed three-level five-phase DTC control strategy, a DSP based experimental system is build. Simulation and experimental results are provided in order to validate the proposed DTC technique.

• 한국농공학회논문집
• /
• 제57권6호
• /
• pp.163-171
• /
• 2015

This study aimed to establish a field observation system for monitoring tempo-spatially precise changes of groundwater level and to analyze the impact of rainfall and irrigation practices on groundwater changes in paddy regions. The monitoring system comprising of all nine groundwater observation wells and four ponding depth sensors was installed in a part of paddy regions benefited from Gosam reservoir, Ansung-si. The result of grundwater level change during the irrigation period in 2002 was averagely 0.51 m higher than that during the non-irrigation period. In particular between March before puddling and June after transplanting, there was maximum 1.23 m rise in groundwater level. On the other hand, concerning the change in ponding depth, groundwater level changed similarly, and hourly rainfall was revealed to have better correlation with 24-hour delayed hourly groundwater level than with the corresponding groundwater level. Eventually, this study could be referenced for further studies to set up a more comprehensive and sustainable monitoring system of groundwater conditions.

• 한국직업건강간호학회지
• /
• 제20권3호
• /
• pp.308-318
• /
• 2011

Purpose: This study was conducted to identify the level of emotional labor, social support, and depressive symptoms of nurses, and the relationships among them. Methods: The data were collected from 314 nurses. Surface and deep-acting scales of the Emotional Labor Scale (ELS), the personal resource questionnaire, the organizational support scale, and the Korean version of the Center for Epidemiologic Studies Rating Scale for Depression (CES-D) were used. Collected data were analyzed by descriptive statistics, t-test, ANOVA, and Scheffe test. Results: Fifty six percent of total subjects had mild or major depressive symptoms. As the level of surface-acting of ELS was higher, so was the level of depressive symptoms, while as the level of individual and organizational support was higher, the level of depressive symptoms was lower. Conclusion: It is necessary to provide organizational-level support and to manage surface-acting in order to prevent the nurses' depressive symptoms. In particular, for the nurses who show relatively higher level of depressive symptoms; who are in 20s and have short employed years or not married, it is urgently required to be provided depressive symptoms management programs that targeted for those nurses.

• The Journal of Asian Finance, Economics and Business
• /
• 제9권5호
• /
• pp.135-145
• /
• 2022

To improve audit quality, certain Chinese auditing firms have added a third-level review by an additional signing auditor to the general evaluation by a signing auditor team consisting of an engagement auditor and a partner. Nonetheless, our research-based on 36,033 firm-year observations from 2004 to 2019 reveals that compared to the general review system, auditor teams under the three-level review system are less likely to issue modified audit opinions when abnormal financial conditions arise. This finding suggests that, while larger auditor teams' knowledge, experience, and information advantages can theoretically sharpen their judgment, their performance is more susceptible to interference from divergent opinions, the diffusion of responsibility, and lower energy invested by individual auditors, ultimately impairing their judgment regarding the audited enterprises' abnormal financial conditions. That is, the three-level review system, which aims to improve audit quality, actually worsens audit quality. This conclusion remains valid after the problems of heteroscedasticity and endogeneity are addressed by using firm-level cluster robust standard errors and two-stage regression. We hope that our research will draw the attention of auditing firms, prompting them to reconsider the rationality of the three-level review system.

• 한국군사과학기술학회지
• /
• 제27권1호
• /
• pp.94-106
• /
• 2024

In this study, we conducted a survival analysis on battalion-level commanders(leaders), focusing on infantry battalion defensive operations using the big data of brigade-level KCTC(Korea Combat Training Center) training results. Unlike previous studies, we utilized the brigade-level KCTC training results data for the first time to conduct a survival analysis, and the research subjects were battalion-level commanders(leaders), which can affect the battle. At this time, the battle results were defined, and through cluster analysis, infantry battalions were divided into excellent, average, and insufficient units, and the difference in the survival rate of the commanders was analyzed through the Kaplan-Meier survival analysis. This provided an opportunity to objectively compare the differences between excellent and insufficient units. Subsequently, factors affecting the survival of commanders were derived using the Cox proportional hazard model, and it was possible to confirm the influencing factors from various angles by also using the survival tree model. Significance and limitations confirmed in the research process were presented as policy suggestions and future research directions.

• 한국치위생학회지
• /
• 제24권1호
• /
• pp.17-26
• /
• 2024

Objectives: This study aimed to analyze the relationship between the socioeconomic status and oral health of adults. Methods: Data from the 7th Korea National Health and Nutrition Examination Survey (2016-2018) were analyzed, and 13,199 adults aged 19 years or older were selected as study subjects. Various oral health indicators were used to analyze the effect of socioeconomic status on oral health. Disparities in oral health according to socioeconomic status were analyzed using the complex sample chi-squared test and multiple logistic regression analysis. Results: A statistically significant difference was observed between income level, medical aid, and all oral health indicators, which indicated that the lower the income level, the lower the oral health level (p<0.001). Furthermore, all oral health indicators displayed statistically significant differences, with the exception of the prevalence of dental caries and education level. The lower the education level, the lower the oral health level (p<0.001). Therefore, the oral health level of adults presented significant differences according to different socioeconomic status indicators. Conclusions: To prevent oral health inequalities, the government and local governments need to intervene not only in the field of health care but also in the social determinants. Additionally, concerted efforts should be made to eliminate oral health disparities by improving policies and systems.

• 한국환경복원기술학회지
• /
• 제7권3호
• /
• pp.78-85
• /
• 2004

The non-planned development of the rural area surrounding the Metropolitan area has become a social problem. The land development program until now has an aspect of not combining the spacial plan and the environmental plan. The land use and city development system based on development should change into a form that combines developing the area and conserving the environment. Therefore, this research attempts to compare the results of the overlay analysis and the gravity matrix which are ways to evaluate the value land that has a high environmental conservation value. The research area is the town of Seonggeo-eup, Cheonan City, and the reason for selecting this area is because it is expected to be densely populated as a connected area to the Metropolitan and the development pressure, such as expanding the industrial area, is high due to convenient transportation. The environmental factors used in the research are the relative altitude, incline, age-class, natural degree of the ecology, classification of the land covering and the NDVI, and the research methods used are the overlay analysis of the GIS and the statistical method. The overlay analysis results showed level 1 13.2%, level 2 30.7%, level 3 47.4%, level 4 1.0%, level 5 2.4%, level 6 5.4% and so on. The gravity matrix was classified as level 1 27.0%, level 2 9.3%, level 3 58.2%, level 4 2.4%, level 5 2.3%, level 6 0.9% and so on. These results are more appropriate than current methods for plans that value the environment because the analyzed results of the gravity matrix have a tendency to highly condense the environmentally valuable area. Consequently, if the spacial and environmental plans combine and therefore expand the efficient use of the land in the current state where the nation's concern in environment is getting higher, it is thought that it will contribute highly on the development of the nation's life quality.

• 디지털융복합연구
• /
• 제12권4호
• /
• pp.33-41
• /
• 2014

본 연구는 다문화가족 청소년 212명을 대상으로 Heater의 이론을 적용하여 그들의 차별경험과 문화변용스트레스 수준을 측정하였고, 이것이 국민정체성에 미치는 영향을 살펴보았다. 본 연구의 주요결과는 다음과 같다. 첫째, 조사대상자들의 차별경험을 측정한 결과 2.63(SD=.72)으로 나타나 보통수준보다 다소 높은 것으로 조사되었으며, 그들의 문화변용스트레스는 2.48(SD=.65)로 나타나 보통수준인 것으로 조사되었다. 둘째, 조사대상자의 국민정체성 수준은 2.16(SD=.57)로 조사되어 보통수준보다 낮은 것으로 나타났으며, 학업수준, 동거부모 형태, 모 한국어능력에 따라 집단별로 유의미한 차이가 나타났다. 셋째, 조사대상자의 차별경험(${\beta}$=-.305), 동거부모 형태(${\beta}$=.286), 문화변용스트레스(${\beta}$=-.225), 학업수준(${\beta}$=.186), 모 한국어 능력(${\beta}$=.173) 등의 순서로 국민정체성에 영향을 미치는 것으로 나타났다. 이러한 연구결과에 기초하여 다문화가족 청소년의 국민정체성을 향상할 수 있는 몇 가지 방안을 제시하였다.