• Sleep Medicine and Psychophysiology
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• v.5 no.1
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• pp.54-70
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• 1998

Objectives : The purpose of this study is to evaluate the role of structural and functional changes of the brain in the pathophysiology of schizophrenia. Methods : The authors measured the regions of interest on the magnetic resonance imaging of the brain in 20 patients with paranoid schizophrenia(15 men and 5 women) and 23 control subjects(15 men and 8 women). We also assessed the neurocognitive functions with the Wisconsin Card Sorting Test, the Benton Neuropsychological Assessment, and the Weschler IQ test-Korean version, soft neurologic signs, and psychiatric symptoms in the patient group. Results : In the patient group, all ventricles and basal ganglia including caudate nucleus and globus pallidus were significantly enlarged. Although there were no significant differences between the two groups in the values of right frontal lobe and left temporal lobe, there was a tendency of decrease in the values of right frontal lobe and left temporal lobe. There were significant positive correlations between the values of ventricles and the frequency of previous hospitalization. However, there were no significant correlations between other values of regions of interest and clinical data. The value of the right frontal lobe was significantly correlated with the score of soft neurologic signs, which is suggestive of the neurodevelopmental abnormalities. There were significant correlations between the value of frontal lobe and the scores of the various subscales of Benton Neuropsychiatric Inventory. In contrast, the value of left amygdala and putamen showed significant correlation with the score of verbal IQ on the Weschler IQ test. Structural changes of the temporal lobe areas were related with the positive and general symptom scores on PANSS, while those of the basal ganglia were related with the negative symptom scores. Conclusions : These results suggest that the structural changes of the brain in the patients with schizophrenia show the dual process, which is suggestive that the enlarged ventricle show the neurodegenerative process, while enlarged basal ganglia, and shrinked right frontal and left temporal lobe show the neurodevelopmental abnormalities. Among these changes, structural changes of the frontal lobe related with various neuropsychological deficits, while those of left temporal lobe related with language abnormality. Relative to the relation between structural changes and psychiatric symptoms, structural changes of the temporal lobe areas were related with the positive and general symptoms, while those of the basal ganglia were related with the negative symptoms.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.618-625
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• 2018

With the passing of time, exposed concrete structures are affected by a range of environmental, chemical, and physical factors. These factors seep into the concrete and have a deleterious influence compared to the initial performance. The importance of identifying and preventing further performance degradation due to the occurrence of deterioration has been greatly emphasized. In recent years, evaluations of the target life have attracted increasing interest. During the freezing-melting effect, a part of the concrete undergoes swelling and shrinking repeatedly. At these times, chloride ions present in seawater penetrate into the concrete, and accelerate the deterioration due to the corrosion of reinforced bars in the concrete structures. For that reason, concrete structures located onshore with a freezing-melting effect are more prone to this type of deterioration than inland structures. The aim of this study was to develop a high performance mortar mixed with a mineral admixture for the durability properties of concrete structures near sea water. In addition, experimental studies were carried out on the strength and durability of mortar. The mixing ratio of the silica fume and meta kaolin was 3, 7 and 10 %, respectively. Furthermore, the ultra-fine fly ash was mixed at 5, 10, 15, and 20%. The mortar specimens prepared by mixing the admixtures were subjected to a static strength test on the 1st and 28th days of age and degradation acceleration tests, such as the chloride ion penetration resistance test, sulfuric acid resistance test, and salt resistant test, were carried out at 28 days of age. The chloride diffusion coefficient was calculated from a series of rapid chloride penetration tests, and used to estimate the life time against corrosion due to chloride ion penetration according to the KCI, ACI, and FIB codes. The life time of mortar with 10% meta kaolin was the longest with a service life of approximately 470 years according to the KCI code.

• Journal of The Korean Association For Science Education
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• v.20 no.3
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• pp.384-395
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• 2000

Recently performance assessments have been recommended as an alternative to traditional assessment methods such as multiple-choice written test. Performance assessment is suggested to facilitate students' creativity, participation and learning motivations in science classes. In this study, performance assessment materials were developed for a biology unit of middle school science 1, 'Plants Around Us', and then the assessment materials were applied to assess students' understandings and attitudes related to each topic of the unit. A total of 186 7th grade students at a southern large city participated in this study. From the study, the following were obtained: 1. Various type of the performance assessment materials, such as observation report, peer evaluation, interview have been developed for the unit 'Plants around us.' 2. Students' understandings on the topics appeared to be sound, and the students' interest and cooperative problem-solving abilities have been cultivated through the small group activities. The science classes became more student-centered. 3. Teacher's burden has increased due to the practices of performance assessment, but it could be handled by teacher's commitment and management skills. 4. The students' responses to performance assessments were positive, in general.

• Korean Journal of Health Education and Promotion
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• v.9 no.1
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• pp.39-47
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• 1992

This study was surveyed among 1136 respondent of high school girls in seoul from Feb. 6, till Feb. 22, 1992 for the purpose of analysing the smoking of high school girls and its factor. The data was analied by X²-test and Multiple Regression and shows the following. 1. Out of 1,136 respondent, the current smokers were found to be 176, 15.5% and the former smokers were 204, 18.0%. This implies that 23.5% of high school girls seoul have experience smoking. 2. For the first smoking time in both smoking group and former smokers, it shows that the third grade of middle school lead the lists. 36.9% (65) of the smokers and 37.3(75)of former smokers experienced the first smoking at that time. 70.5%(124) of the smoking group have the intention to stop smoking and the first reason of it is health problem, 65.6%(75). 3. For the type of the school the smoking rate rages from 2.7%(7) of literary part in day time to 25.3%(97) of vocational part in evening time and the rate of smoking experience shows from 9.9%(26) literary part in day time to 25.3%(97) of vocational part in evening time. This data show that literary part in day time has the lowst rate while vocational part in eveing time the highest rate. 4. Compared with non smoker group, smoking group and former smoking group spent more money (P<0.001) and felt dissatisfied with school life and didn't have good school records. 5. Smoking group and former smokers have more boy friends than non smoking group and in most cases their boy friend have smoking habits (P<0.001) and it is the same with their gril friend (P<0.001). 6. Compared with non smoker group, smoking group and former smokers lack of their parents' interest (P<0.001). But whether it is strict or free there is little difference among the three group. 7. For smoking group and former smoking group, in most cases their parent, brother and sister tend to smoke and especially their sisters' smoking has much influence on their smoking in comparison with non-smokers. 8. Compared with non-smoker group, smoking group and former smoking group tend to think less of the harm of smoking. In regard with health problem, more smoking group and former smokers think that smoking can relieve the stress (P<0.001), and more non-smokers know that when a pregnant woman smokes, it can cause the lack of supply of Oxygen{P<0.01). 9. Smoking group and former smoking group have more positive attitude towards smoking than non-smokers and tend to agree to their boy and girl friends' smoking(P<0.001).

• Korean Journal of Construction Engineering and Management
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• v.11 no.6
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• pp.111-121
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• 2010

As the customer's interest for sidewalk block in the street or apartment complex is increasing, the materials of block which had been a concrete block exclusively are varied to clay paver, native rock and wood etc. Especially, the sales volume of clay paver which is environment-friendly and ergonomic is dramatically increasing every year with two digits growth rate, however, many problems like "Edge Cracking" "Freezing Breakage" "Bending Breakage" "Joint Gap" are happening frequently within a couple of hours after installation due to the durabilities. Because of the characteristics of Ceramic products, clay pavers are very easy to be broken when they are bumped against each other. In addition, they are relatively fragile by a freezing expansion breakage when exposed to water due to hydrophilic property as well as the intensity and absorptance of the products are varied with small difference from the production process such as production equipment and process control. Therefore, it costs a lot of money to repair the breakdown unless production and installation is carried out according to the strict criteria of the quality control. In this study, the symptoms of breakdown frequently happened in clay paver are classified by each type and finally the solution for this problem in the production of brick, installation and criteria of quality control through compressive strength and absorptance test is suggested.

• Journal of the Korea Institute of Building Construction
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• v.12 no.2
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• pp.203-210
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• 2012

Recently, the interest and demand for large-scale buildings and skyscrapers have been on the rise, and the performance of concrete is an area of high priority. Securing 'mass concrete and high strength concrete' is very important as a key construction technology. For high strength concrete, the high heat of hydration takes place inside the concrete because of the vitality of hydration in cement due to the large amount of powder, and leads to problems such as an increase of thermal stress due to the temperature difference with the outside, which results in cracks and slump loss. For this reason, measures to solve these problems are needed. This study aims to reduce the hydration heat of high strength concrete to control the hydration heat of mass concrete and high strength concrete, by replacing the type of admixture, The purpose of this study is to control the hydration heat of high strength concrete and mass concrete. Our idea for this purpose is to apply not only the types and contents of admixture but also incorporation mixing water to ice-flake. As a result of the test, the use of blast furnace slag and fly ash as admixture, and the use of ice-flake as mixing water can improve the liquidity of concrete and reduce slump loss. Significantly dropping the maximum temperature will contribute greatly to reducing cracks due to hydration heat in mass concrete and high strength concrete, and improve quality.

• Research in Plant Disease
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• v.17 no.1
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• pp.25-31
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• 2011

Rust causes significant losses in the yield and quality of various crops. The development of new effective and environmentally benign agents against the pathogen is of great interest. In the course of searching a natural antifungal compound from medicinal plants, we found that the methanol extract of Angelica gigas roots had a potent control efficacy against wheat leaf rust (WLR) caused by Puccinia recondita. The antifungal substance was isolated from the methanol extract by silica gel column chromatography, alumina column chromatography and $C_{18}$ preparative HPLC. It was identified as decursinol angelate by EI-MS and $^1H$-NMR data. In in vivo test, decursinol angelate effectively suppressed the development of WLR and red pepper anthracnose (RPA) among the 6 plant diseases tested. In addition, the wettable powder-type formulation of ethyl acetate extract of A. gigas roots significantly suppressed the development of WLR. The crude extract containing decursinol angelate and the chemical appear to be a potential candidate for control of WLR. In addition, this is the first report on the in vivo antifungal activity of decursinol angelate against WLR as well as RPA.

• Clean Technology
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• v.20 no.4
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• pp.433-438
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• 2014

There is an increasing interest in the development of rechargeable batteries suitable for use in both hybrid electric vehicles and energy storage systems that require higher charge & discharge rates, bigger battery sizes and increased safety of the batteries. Spinel-type lithium titanium oxide ($Li_4Ti_5O_{12}$) as a potential anode for lithium ion batteries has many advantages. It is a zero-strain materials and it experiences no structural change during the charge/discharge precess. Thus, it has long cycle life due to its structural integrity. It also offers a stable operation voltage of approximately 1.55 V versus $Li^+/Li$, above the reduction potential of most organic electrolyte. In this study, Ru added $Li_4Ti_5O_{12}$ composites were synthesized by solid state process. The characteristics of active material were investigated with TGA-DTA, XRD, SEM and charge/discharge test. The capacity was reduced when Ru was added, however, the polarization decreased. The capacity rate of $Li_4Ti_5O_{12}$ with Ru (3%, 4%) addition was reduced during the charge/discharge precess with 10 C-rate as a high current density.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.577-586
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• 2021

This study analyzed the research trends related to parenting stress of parents with infancy. To this end, 82 papers in journals registered in the KCI from 1998 to 2019 were reviewed. The frequency and percentage were calculated and analyzed for each research period, research topic, research type, and research subject. The research results were as follows. First, from 1998 to 2019, there was a continuous increase in each period. Second, regarding the research subject, the themes related to parents were the most researched, followed by the child, parenting environment, and parent-child. Among the topics related to parents, research on the variables related to parenting beliefs and behaviors was the highest. Third, quantitative research was absolute, and no qualitative research was conducted. Among the quantitative studies, the most common test method was through a questionnaire. Fourth, regarding each research subject, the research of mothers was dominant, followed by mother-infant, parent, and parent-infant-teacher. This study is significant because it provides an opportunity to broaden the scope of research and academic interest in the parenting stress of infancy parents.

• Health Policy and Management
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• v.31 no.1
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• pp.74-90
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• 2021

Background: It is getting important to improve the oral health status of the elderly because oral health status may affect their health status of the whole body. In this respect, we aimed to explore the association of oral health status and behavior factors with self-rated health status by sex. Methods: Using the data from the 7th Korea National Health and Nutrition Examination Survey for health surveys and oral examinations (2016-2018), we analyzed a total of 3,070 people aged 65 or older (men: 1,329; women: 1,741). Our dependent variable, self-rated health status, was divided into two groups: not good (bad and very bad) and good (very good, good, and fair), whereas our independent variables of interest were oral health status and behavior factors. In addition to descriptive analysis and the Rao-Scott chi-square test, reflecting survey characteristics, we conducted hierarchical multivariable logistic regression analyses adjusted for socio-demographics and health status and behavior factors. All analyses were stratified by sex. Results: The proportion of people having 'not good' self-rated health was 36.5% in women but 24.5% in men. In a model adjusted for all covariates, the self-rated health status showed significant association with the self-rated oral health status. For example, in men, the risk of having 'not good' self-rated health was high in people having 'poor' (odds ratio [OR], 5.31; 95% confidence interval [CI], 2.34-12.03) self-rated oral health status and in those having 'fair' (OR, 4.03; 95% CI, 1.68-9.70) in comparison with those having 'good' self-rated oral health status. Dental status regarding speaking difficulty seemed to be very important in influencing self-rated health status. For instance, in women, compared to people having 'no discomfort' speaking difficulty, the risk of having 'not good' self-rated health was high in people having 'not bad' (OR, 1.60; 95% CI, 1.14-2.24) and 'discomfort' (OR, 1.79; 95% CI, 1.30-2.47) speaking difficulty. The covariates significantly associated with the risk of having 'not good' self-rated health were: physical activity, chronic disease, stress, and body mass index in both sexes; health insurance type and drinking only in men; and economic activity only in women. Conclusion: Oral health status and behavioral factors were associated with self-rated health status among the elderly, differently by sex. This suggests that public health policies toward better health in the elderly should take their oral health status and oral health behaviors into account in a sex-specific way.