• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.1
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• pp.174-182
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• 2007

In this paper, we study the influence of infection ratio on gradual reduction of drug dose for the five state HIV infection model that explicitly includes the population of the virus. We first compute all equilibrium points of the model and investigate the stabilities of them. As a result, a bifurcation diagram is obtained which shows a change in the equilibrium points, or in their stability properties, as the drug effect $\eta$ is varied from 0 to 1(alternatively, drug dose is changed from 1 to 0). Based on the bifurcation diagram, we show that the gradual reduction of drug dose can be applied for the treatment of AIDS patients. Moreover, we analyze the influence of the variation of infection ratio on the gradual reduction treatment. Computer simulation results are also presented to validate the proposed results.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.18 no.1
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• pp.37-45
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• 2011

Purpose: The purpose of this study was to estimate the effects of an infection control program on the Clonorchis sinensis (CS) infection ratio, CS-related knowledge and health behavior of people living near the Geum River. Method: A one-group pretest-posttest design was used with 102 participants. For 12 months the participants were provided with promotion announcements, health education, counseling, and medication. Outcome variables measured were the CS infection ratio by stool examination, CS-related knowledge and health behavior from self-report questionnaires. The pre intervention data were collected from January to February 2008 and the post intervention data during the same period in 2009. Collected data were analyzed using descriptive statistics, generalized estimating equation analysis, and paired t-test with SPSS for Windows version 15.0. Results: In the pre test 21 of the 102 participants showed infection with CS for the first time. In the post test 9 were newly infected with CS, and one was re-infected. The CS-related knowledge was significantly improved after the infection control program (p<0.05). The CS-related health behaviors did not improve. Conclusion: These results showed that an infection control program is effective in decreasing CS infection ratio and improving CS-related knowledge of people living near the river.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.04a
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• pp.52-52
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• 2018

Apple (Malus domestica) is one of the most economically important fruits in Korea. But virus infection has decreased sustainable production of apple and caused the serious problems such as yield loss and poor fruit quality. Virus or viroid infection including Apple chlorotic leaf spot virus (ACLSV), Apple stem pitting virus (ASPV), Apple stem grooving virus (ASGV), Apple mosaic virus (ApMV) and Apple scar skin viroid (ASSVd) has been also reported in Korea, furthermore, its damages and economic losses have increased constantly. In our research, we tried to survey virus infection for commercial nursery trees of major apple cultivars, especially dwarfing rootstocks 'M.9' and 'M.26' as well as scions. Trees were collected from 11 locations which have produced a great amount of apple nursery stocks in Korea. Infection degree was investigated in apple cultivars, 'Hongro' and 'Fuji' using RT-PCR method. In the scion of cultivar 'Hongro', infection ratio of ACLSV, ASPV and ASGV were 100%, 81.8% and 100% respectively. In the rootstock of cultivar 'Hongro', infection ratio of ACLSV, ASPV, ASGV and ApMV were 90.9%, 81.8%, 100% and 9.1% respectively. In the scion of cultivar 'Fuji', infection ratio of ACLSV, ASPV and ASGV were 81.8%, 90.9% and 100% respectively. In the rootstock of cultivar 'Fuji', infection ratio of ACLSV, ASPV, ASGV and ApMV were 81.8%, 90.9%, 100% and 9.1% respectively. Infection of ASSVd was not detected in both cultivars. From our results, it was found that most of apple rootstocks and scions had multiple infections by apple viruses which have caused economic damage in fruit production.

• Korean Journal of Health Education and Promotion
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• v.27 no.1
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• pp.1-8
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• 2010

Objectives: Human papillomavirus (HPV) infection is highly associated with cervical cancer. So, the modification of the risk factors of HPV infection is essential for prevention of cervical cancer. This study was performed to evaluate the risk factors of HPV infection. Methods: HPV test of 12,337 study population conducted using Hybrid-Capture II assay(HC-II) and self-administered questionnaires were collected. The study population was people who visited hospital-based medical screening center from January to December 2007 and all were female employees or employees' partner. Results: In logistic regression analysis, smoking and alcohol drinking were significant factors, with odds ratios of 1.328 (95% CI 1.010~1.746) and 1.644 (95% CI 1.309~2.066), respectively. Nutritional supplements was also significant factor, which odds ratio was 1.161 (95% CI 1.004~1.343). Oral contraceptives was positive association with HPV infection (odds ratio 2.108; 95% CI 1.217~3.652), whereas condom was negative association (odds ratio 0.851; 95% CI 0.740~0.979). Conclusion: HPV Prevalence of 12,377 study population was 11.4%. Smoking, alcohol drinking, nutritional supplements and oral contraceptives were possible risk factors of HPV infection, and condom had possible preventive effect on HPV infection. Further prospective and comprehensive studies about HPV risk factors are required.

• Journal of Environmental Science International
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• v.26 no.7
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• pp.803-815
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• 2017

In this study of the oak wilt disease that has occurred in a large scale in a protected area located near South Korea's metropolitan region, a detailed analysis has been conducted on the terrain, species and Diameters at Breast Height (DBH) of infected trees to identify the distribution of infection properties in the affected area. Taking into consideration the distribution of oak tree vegetation, a total of 4,640 quadrats in a size of 10 m by 10 m, have been set; and oak tree species, the DBH and infection damage per quadrat have been investigated. Geological properties have been analyzed according to elevation, slope, aspect and micro topography while a weighted value has been given according to the degree of infection in order to calculate an infection index. Through correlation analysis, the infection ratio of seriously-damaged and withered trees and the infection index have been analyzed with regards to the geological properties, tree species and DBH. The analysis shows that the disease tends to affect an area with medium elevation rather than those in the highest or lowest areas and that serious damage has been observed at rugged spots with a steep gradient (more than $30^{\circ}$). Although there has been no distinct tendency with regards to aspect, the infection ratio is relatively high in areas facing the north while the seriously-damaged and withered ratio are high in areas facing the south. In terms of micro topography, more damage has been spotted in valley terrain. Quercus mongolica has sustained more damage than other species. When it comes to the DBH, as seen in previous studies, large trees have suffered severe damage, but the analysis has also revealed conspicuous damage to medium trees with a DBH of 15-20 cm, which had not previously been considered at high risk.

• Journal of dental hygiene science
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• v.7 no.4
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• pp.263-269
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• 2007

To investigate the actual conditions management of infectious prevention in dental office, questionnaire about infection control and education of infection control was performed on 50 dentists, 176 dental hygienists, 100 aide nurses who are working in Deagu City from march to April, 2007. The results are as the following. Dentists are the highest on the health inspection's ratio, dental hygienists are the highest on vaccination's ratio. Experience ratio about education of infection control is the highest on dentist and the lowest on aide nurses(p < 0.05). Dental hygienists are higher than dentists and aide nurses on ratio of wearing protective gear(p < 0.05). Dentists have the highest ratio on washing hands after treat(p < 0.05). Practice of instrument's sterilization is higher in dental hygienist than other groups. Disinfection of equipment's surface practice mainly on bracket table, dental hygienist's ratio is the highest among the three groups.

• Journal of the Korean Society of Clothing and Textiles
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• v.18 no.5
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• pp.615-621
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• 1994

This study was carried out to investigate the effect of clothing habit on physiological adaptation to the change of season. The survey of clothing weight in fall '||'&'||' winter for 2 years, the frequency of cold infection in winter and degree of fatigue was performed with 110 female high school students. The actual condition of clothing and the correlations between clothing weight and cold infection, and between the clothing weight and degree of fatigue were suveyed. The results are followed as; 1. The clothing insulation was nearly same to indoor standard clothing insulation in H hun wearing normal clothing, but was higher 2 clo in S hun clothed uniform. Especially in spite of similar enviromental condition the clothing weight, minimum '||'&'||' maximum and variation of clothing weight for 2 years were showed to be heavier in S hun than H hun. Also indoor thermal sensation felt by the subjects indicated "cold", and the difference between clothing insulation and standard clothing insulation showed increase gradually. 2. L group was indicated to be lower in cold infaction ratio than M '||'&'||' H group, and the correlation between clothing group and cold infection ratio was recognized to be significant (p<0.05). And H hun and L-H group showed to be lower in cold infection ratio than S hun, H-L group. 3. The coefficience between clothing weight and degree of fatigue was recognized to be significant (p<0.05).

• Tuberculosis and Respiratory Diseases
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• v.72 no.2
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• pp.140-148
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• 2012

Background: Detection and treatment of tuberculosis (TB) infection with contact investigation is a key component of TB control program. I evaluated the prevalence and risk factors for TB infection among contacts of recently diagnosed pulmonary TB patients in a tertiary hospital in Korea. Methods: 206 contacts of 90 adult pulmonary TB patients underwent tuberculin skin tests (TST) and chest radiography. The TST results were considered positive with an induration of 10 mm or more, suggesting TB infection. A standardized questionnaire was used to assess risk factors associated with TB infection. Results: TST was positive in 97 of 206 contacts of TB patients (47.1%) and positive rate of TST increased with age. The risk of TB infection was significantly associated with close contact with TB patients (sleeping in the same room) (odd ratio [OR], 4.94; 95% confidence interval [CI], 1.43~17.00). Conclusion: TB infection rate was higher in the elderly, and the risk of TB infection was significantly increased with close contact of TB patients.

• Research in Plant Disease
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• v.23 no.4
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• pp.355-362
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• 2017

The 4 viruses, the Apple chlorotic leaf spot virus (ACLSV), Apple stem pitting virus (ASPV), Apple stem grooving virus (ASGV), and Apple mosaic virus (ApMV) and 1 viroid, Apple scar skin viroid (ASSVd) are known major viral pathogens of apple trees in Korea. Infection degree of the 5 viral pathogens in the commercial nursery trees of major apple cultivars, 'Hongro', 'Fuji' and bud mutation of 'Fuji' was investigated. Infection ratio of the ACLSV, ASPV and ASGV for scion of an apple cultivar 'Hongro' were 100%, 81.3% and 100%, respectively. On the other hand, no infection for either ApMV and ASSVd detected. For the root stock of the cultivar, infection ratio of ACLSV, ASPV and ASGV showed 87.5%, 81.3% and 100% as well as ApMV and ASSVd were 12.5% and 6.3%, respectively. From the scion of apple cultivars 'Fuji' and bud mutation of 'Fuji', infection ratio of ACLSV, ASPV and ASGV showed 86.7%, 86.7% and 100%, respectively. Whereas, no infection for either ApMV or ASSVd detected. From the root stock of the cultivars, infection ratio of ACLSV, ASPV and ASGV showed 86.7%, 93.3% and 93.3% as well as ApMV and ASSVd were 12.5% and 6.3%, respectively. Result of our study indicates that most of commercial nursery apple trees were supplied with multiple infections by apple viruses causing potential losses for apple growers and, henceforth, agricultural policy for supply of the virus-free trees should be employed as soon as possible.

• Korean Journal of Veterinary Research
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• v.31 no.1
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• pp.99-108
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• 1991

To observe the changes of serum proteins according to the process of Babesia gibsoni(B gibsoni) infection, the babesia protozoa($10^8/kg$) were inoculated into the cephalic vein of healthy dogs. The serum proteins of experimentally infected dogs were separated by using cellulose acetate electrophoresis. The results obtained were as follows; 1. Cellulose acetate electrophoresis was fractionated to total 6 of bands such as, albumin, ${\alpha}_1$, ${\alpha}_2$, ${\beta}_1$, ${\beta}_2$ and $\gamma$-globulin. 2. The concentration of total protein was shown a decreasing tendency after B gibsoni infection. Albumin and A/G ratio were lowered through all periods of the infection, but they were not significant changes. 3. The level of ${\alpha}_1$-globulin was significantly(p<0.05) incresed in early stage of the infection. 4. The levels of ${\alpha}_2$ and total $\alpha$-globulin were shown highly significant decreases (p<0.01) through all periods of the infection. 5. The levels of ${\beta}_1$ and total $\beta$-globulin had highly significant changes (p<0.01) that was increased in early stage of infection and decreased later. 6. The level of $\gamma$-globulin was seen to be constantly increased through all periods of infection. It was a highly significant change (p<0.01). 7. Plasma protein: fibrinogen (PP:F) ratio was shown a temporally significant increase (p<0.05) following the decrease in early infection.