• Journal of the Korean Vacuum Society
• /
• v.15 no.1
• /
• pp.89-96
• /
• 2006

Recent ULSI and multilevel structure trends in microelectronic devices minimize the line width down to less than $0.25{\mu}m$, which results in high current densities in thin film interconnections. Under high current densities, an EM(electromigration) induced failure becomes one of the critical problems in a microelectronic device. This study is to improve thin film interconnection materials by investigating the EM characteristics in Ag, Cu, Au, and Al thin films, etc. EM resistance characteristics of Ag, Cu, Au, and Al thin films with high electrical conductivities were investigated by measuring the activation energies from the TTF (Time-to-Failure) analysis. Optical microscope and XPS (X-ray photoelectron spectroscopy) analysis were used for the failure analysis in thin films. Cu thin films showed relatively high activation energy for the electromigration. Thus Cu thin films may be potentially good candidate for the next choice of advanced thin film interconnection materials where high current density and good EM resitance are required. Passivated Al thin films showed the increased MTF(Mean-time-to-Failure) values, that is, the increased EM resistance characteristics due to the dielectric passivation effects at the interface between the dielectric overlayer and the thin film interconnection materials.

• The Journal of the Korea Contents Association
• /
• v.18 no.3
• /
• pp.256-264
• /
• 2018

The purpose of this study was to investigate the relationship between oral health behaviors and the results of the oral dysentery test for dental hygienists and students at Gyeonggi - do and Chungcheongnam - do. Self - filling questionnaires and oral diseases. The following conclusions were obtained. The most common toothbrushing frequency was three times a day (60.2%), and the most dominant frequency of eating between meals was once or less(49.7%). The most common snack that they had was stickiness-free sweetened food(66.5%), and the type of beverage that they had the most was sweetened beverages(49.7%). The average stimulated saliva flow rate was 9.41ml, and they got a mean of 9.52 in the buffering capacity of saliva. The average glucose clearance time was a mean of 12.02. When they took a streptococcus mutans colony count test, 80.1 percent belonged to the low-risk group(<$10^5$), and 82.6 percent belonged to the low-risk group(<$10^5$) when a lactobacillus test was conducted. There was a positive correlation between the irritant saliva fraction and the non-irritating saliva and saliva buffering ability. In the fluoride application experience, the glucose retention time was 10.66 minutes and the fluoride application experience was 13.33 minutes. (P = .008). The importance of oral health, which is directly linked to general health, should be emphasized in order to improve the quality of life as well as the life expectancy. For oral health, which is directly linked to systemic health, it is necessary to provide opportunities for oral health education that can be easily accessed by the public, and to continuously develop and provide oral health care programs for a lifetime.

• Asian Pacific Journal of Cancer Prevention
• /
• v.16 no.15
• /
• pp.6521-6526
• /
• 2015

Background: This study aimed toanalyze the risk behavior for cervical cancer (CC) and the human papillomavirus (HPV) prevalence and resolution among women who received care through the private healthcare network of a municipality in southern Brazil. Materials and Methods: This descriptive and retrospective study was conducted with 25 women aged 20 to 59 years who received care through the private healthcare network and were treated at a specialty clinic in the period from January to December 2012 in a municipality in Northwest Parana, Southern Brazil. Data from medical records with cytological and HPV results were used. Following treatment, these women were followed-up and reassessed after 6 months. Data were statistically analyzed using the t-test and chi-squared test at a 5% significance level. Results: The mean age of the studied women was $27.8{\pm}7.75$ years old, and the majority were married, with paid employment and were non-smokers. The mean age at menarche was $13.0{\pm}0.50$ years old, and the mean age at first intercourse was $17.5{\pm}1.78$ years, with only 8.0% (2) initiating sexual activity at an age ${\leq}15$ years old. The majority had 1 to 2 children (60.0%), while 88.0% reported having had one sexual partner in their lifetime, and all the women were sexually active. A total of 68.0% used a hormonal contraceptive method. All the women had leukorrhea and pain and were infected by a single HPV type. Regarding the lesion grade, 80.0% showed high risk and 20.0% low risk. The most prevalent high-risk HPV strain was 16. Conclusions: These findings provide relevant information on HPV risk factors and infection, as well as the treatment and 6-month follow-up results, in economically and socially advantaged women with no traditional risk factors, corroborating previous reports that different risk factors may be described in different populations. Thus, this study reinforces the fact that even women without the traditional risk factors should undergo HPVmonitoring and assessment to determine the persistence of infection, promoting early diagnosis of the lesions presented and appropriate treatment to thus prevent the occurrence of CC.

• Journal of Ocean Engineering and Technology
• /
• v.25 no.2
• /
• pp.85-91
• /
• 2011

Many protection methods such as surface coating, electric protection, or other methods have been applied to the numerous steel structures widely used in continental and marine areas to control their corrosion, which is done from an economic point of view. Most of these steel structures are primarily protected by coating methods. However, some steel piles under seawater are protected by the electric protection method, that is, either using an impressed current or a sacrificial anode method. Furthermore, environmental contamination may cause a severely corrosive environment, which, in turn, causes the accelerated corrosion of steel structures. Subsequently, coated steel structures could deteriorate more rapidly than the designed lifetime because of the acid rain caused by air pollution, etc. Therefore, a coating of marine paint exposed to seawater, that is, underwater hardening painting, is increasingly required to be fast drying as well as highly corrosion resistant. In this study, five types of underwater hardening paints were prepared with different resin series and additives. Their corrosion and water resistances were investigated using electrochemical methods such as corrosion potential, polarization curves, impedance and cyclic voltammogram measurements, etc. Even though it is generally accepted that the corrosion resistance of bare steel tends to increase with a shift of the corrosion potential in the noble direction, the corrosion resistance of a sample with a coating exhibited a relatively better tendency when it had a lower corrosion potential in this study. The corrosion current density was also decreased with a decrease in the diffusion limiting current density, which may mean that there is some relationship between corrosion and water resistance. The S sample of the ceramic resin series showed the relatively best corrosion and water resistance among those of samples, while the worst corrosion and water resistance were observed for the R sample of the epoxy resin series. The corrosion and water resistance of those samples tended to deteriorate with an increase in the immersion days, and their corrosion and water resistances were considered to be apparently improved by the types of resin and additives.

• Journal of Environmental Health Sciences
• /
• v.46 no.5
• /
• pp.576-587
• /
• 2020

Objectives: This study calculated local residents exposures to VOCs (Volatile Organic Compounds) released into the atmosphere using the CalTOX model and carried out uncertainty analysis and sensitivity analysis. The model validity was analyzed by comparing the predicted and the actual atmospheric concentrations. Methods: Uncertainty was parsed by conducting a Monte Carlo simulation. Sensitivity was dissected with the regression (coefficients) method. The model validity was analyzed by applying r² (coefficient of determination), RMSE (root mean square error), and the Nash-Sutcliffe EI (efficiency index) formula. Results: Among the concentrations in the atmosphere in this study, benzene was the highest and the lifetime average daily dose of benzene and the average daily dose of xylene were high. In terms of the sensitivity analysis outcome, the source term to air, exposure time, indoors resting (ETri), exposure time, outdoors at home (ETao), yearly average wind speed (v_w), contaminated area in ㎡ (Area), active breathing rate (BRa), resting breathing rate (BRr), exposure time, and active indoors (ETai) were elicited as input variables having great influence upon this model. In consequence of inspecting the validity of the model, r² appeared to be a value close to 1 and RMSE appeared to be a value close to 0, but EI indicated unacceptable model efficiency. To supplement this value, the regression formula was derived for benzene with y=0.002+15.48x, ethylbenzene with y ≡ 0.001+57.240x, styrene with y=0.000+42.249x, toluene with y=0.004+91.588x, and xylene with y=0.000+0.007x. Conclusions: In consequence of inspecting the validity of the model, r² appeared to be a value close to 1 and RMSE appeared to be a value close to 0, but EI indicated unacceptable model efficiency. This will be able to be used as base data for securing the accuracy and reliability of the model.

• Journal of Preventive Medicine and Public Health
• /
• v.37 no.2
• /
• pp.166-173
• /
• 2004

Objectives : Cervical cancer is the second most frequent cancer among women in Busan. The Pap smear test could have a significant effect on detecting cervical cancer, and enhancing their rate of use is an important strategy for reducing the incidence and mortality of cervical cancer. This study aimed to evaluate the factors associated with the past use of the Pap smear test in Korean women. Methods : A population-based survey was carried out in Busan between November 1999 and March 2000. 1,673 participants were randomly selected from 2,684 women in Busan, using a 2-stage cluster sampling method, and interviewed in their homes. Their socio-demographic characteristics, smoking, drinking, familial cancer history, Pap smear screening history, reproductive and menstrual factors, sexual habits and use of contraceptive methods data were collected by a trained interviewer using a questionnaire. The use of the screening test was defined by a self-report from the participants on how many times they had had a Pap smear test in their lifetime, and when they had received their latest examination. Results : Of the 1,673 respondents (62.3% response rate), 57.6% had had a Pap smear test during her life (mean number, 2.3). Among the health examination participants(1,064), 961(90.3%) reported having sexual experience and 70.9% of these had had a Pap smear test. In a multiple logistic regression analysis, statistically significant relationships were observed for age groups and the Pap smear test rate (odds ratio, OR for 35-44 years=2.45; OR for 45-54 years=3.41; OR for 55 years=2.60; reference, under 34 years). The married or cohabiting women were more likely to have used the Pap smear test than those separated or widowed (OR=1.73). Among the reproductive behavioral measures, the number of births (OR for 3 births=4.22; OR for 2 births=3.95; OR for 1 births=3.38; reference, 0 births) and husband's extra-marital affairs (OR=1.50) were associated with the rates of use of Pap smear tests. Conclusion : It appears that the most important contributing factors to cervical cancer screening were age, marital status and number of births. A positive association was also observed for the husband's extra-marital affairs. This study enabled us to systematically assess the relationship between Pap smear rates and risk factors for cervical cancer. It is hoped that this study will make a significant contribution to the accumulating scientific evidence on the identification of factors associated with cervical cancer screening in Korea.

• Journal of Environmental Health Sciences
• /
• v.39 no.5
• /
• pp.408-417
• /
• 2013

Objectives: Phthalates are used as plasticizers in polyvinyl chloride (PVC) plastics. As phthalate plasticizers are not chemically bound to the PVC, they can leach, migrate or evaporate into indoor air and atmosphere, foodstuffs, other materials, etc. Therefore, humans are exposed through ingestion, inhalation, and dermal exposure over their entire lifetime, including during intrauterine development. In particular, university students have a great number of opportunities to contact products including phthalates during campus life (food packaging, body care products, cosmetic, lotions, aftershave, perfume etc.). The purpose of this study was to examine levels of phthalate exposure as undergraduate students begin to use pharmaceuticals and personal care products including phthalates. Methods: Phthalate metabolites, mono-ethyl phthalate (MEP), mono-n-butyl phthalate (MnBP), mono-isobutyl phthalate (MiBP), mono-2- ethylhexyl phthalate (MEHP), {(mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP}, and mono-(2-ethlyl-5-oxohexyl) phthalate (MEOHP} were examined. 80 urine samples collected from university students were analyzed using LC/MS/MS(API 4000, Applied Bioscience) with on-line enrichment and columnswitching techniques. This study was carried out at Y university located in Gyonggi Province from 2008 to 2011. Results: The detection limit of phthalate metabolites were 0.03 ng/mL for MEP, 0.11 ng/mL for MnBP, 0.08 ng/mL for MiBP, 0.93 ng/mL for MEHP, 0.19 ng/mL for MEOHP and 0.16ng/mL for MEHHP. MnBP showed the highest urinary levels (median: 31.6 ug/L, 24.8 ug/g creatinine (cr)). Concentrations were also high for MEHHP (median: 24.1 ug/L, 19.0 ug/g cr), followed by MEOHP (median: 22.8 ug/L, 17.9 ug/g cr). In individual cases, the maximum level reached up to 348 ug/L, and 291 ug/g cr, respectively. The urinary and creatinine adjusted levels of MEP were lower than those for DBP and DEHP metabolites, but were higher in 95th percentiles. As a result, the mean daily DEP intake value was 2.3 ${\mu}g/kg$ bw/day, 3.5 ${\mu}g/kg$ bw/day for DEHP and 4.9 ${\mu}g/kg$ bw/day for DBP. Conclusion: These students' phthalate exposure levels were below the international safe level set by the EU, but higher than the 2012 KFDA survey of the age group from 3 to 18.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.10 no.5
• /
• pp.372-379
• /
• 2017

Software reliability factor during the software development process is elementary. Case of the infinite failure NHPP for identifying software failure, the occurrence rates per fault (hazard function) have the characteristic point that is constant, increases and decreases. In this paper, we propose a reliability model using the chi - square distribution which depends on the degree of freedom that represents the application efficiency of software reliability. Algorithm to estimate the parameters used to the maximum likelihood estimator and bisection method, a model selection based on the mean square error (MSE) and coefficient of determination($R^2$), for the sake of the efficient model, were employed. For the reliability model using the proposed degree of freedom of the chi - square distribution, the failure analysis using the actual failure interval data was applied. Fault data analysis is compared with the intensity function using the degree of freedom of the chi - square distribution. For the insurance about the reliability of a data, the Laplace trend test was employed. In this study, the chi-square distribution model depends on the degree of freedom, is also efficient about reliability because have the coefficient of determination is 90% or more, in the ground of the basic model, can used as a applied model. From this paper, the software development designer must be applied life distribution by the applied basic knowledge of the software to confirm failure modes which may be applied.

• Food Science of Animal Resources
• /
• v.31 no.6
• /
• pp.960-965
• /
• 2011

The content of benzo[a]pyrene from 69 smoked meat products commonly consumed in Korean food market was analysed with high performance liquid chromatography. Smoked meat products including smoked chicken, pork, turkey and duck were saponified, extracted and cleaned up to analyze the benzo[a]pyrene content. As a result of analysis from smoked meat products, the mean benzo[a]pyrene content was 0.42 ${\mu}g$/kg and the highest content of benzo[a]pyrene was 2.87 ${\mu}g$/kg detected in smoked chicken product. All somked meat products contained benzo[a]pyrene below the limit regulated by Korean Food and Drug Administration (KFDA). Exposure assessment of benzo[a]pyrene from smoked meat products ingestion was calculated by using National Health and Nutrition Survey (NHNS). The estimated lifetime average daily intake of benzo[a]pyrene was 0.187 ng/kg bw/d. Margin of exposure of benzo[a]pyrene was ranged from 1,657,754 to 3,957,219.

• Asian Pacific Journal of Cancer Prevention
• /
• v.14 no.10
• /
• pp.5877-5882
• /
• 2013

Background: The aim of the study was to determine breast cancer risk and early diagnosis applications in women aged ${\geq}50$. Materials and Methods: This cross-sectional, descriptive field study focused on a population of 4,815 in Mansuro$\breve{g}$lu with a 55.1% participation rate in screening. In the study, body mass index (BMI) was also evaluated in the calculation of breast cancer risk by the Breast Cancer Risk Assessment Tool (BCRA) (also called the "Gail Risk Assessment Tool"). The interviewers had a three-hour training provided by the researchers, during which interactive training methods were used and applications were supported with role-plays. Results: The mean age of the women participating in the study was $60.1{\pm}8.80$. Of these women, 57.3% were in the 50-59 age group, 71.7% were married, 57.3% were primary school graduates and 61.7% were housewives. Breast-cancer development rate was 7.4% in the women participating in the study. When they were evaluated according to their relationship with those with breast cancer, it was determined that 73.0% of them had firstdegree relatives with breast cancer. According to the assessment based on the Gail method, the women's breast cancer development risk within the next 5 years was 17.6%, whereas their calculated lifetime risk was found to be as low as 0.2%. Statistically significant differences (P=0.000) were determined between performing BSE-CBE and socio-demographic factors. Conclusions: It was determined that 17.6% of the participants had breast cancer risk. There was no statistically significant difference between the women with and without breast cancer risk in terms of early diagnosis practices, which can be regarded as a remarkable finding. It was planned to provide training about the early diagnosis and treatment of breast cancer for people with high-risk scores, and to conduct population-based breast cancer screening programs.