• Nuclear Medicine and Molecular Imaging
• /
• v.41 no.4
• /
• pp.317-325
• /
• 2007

Purpose: Biological parameters can be quantified using dynamic PET data with compartment modeling and Nonlinear Least Square (NLS) estimation. However, the generation of parametric images using the NLS is not appropriate because of the initial value problem and excessive computation time. In irreversible model, Patlak graphical analysis (PGA) has been commonly used as an alternative to the NLS method. In PGA, however, the start time ($t^*$, time where linear phase starts) has to be determined. In this study, we suggest a new Multiple Linear Analysis for irreversible radiotracer (MLAIR) to estimate fluoride bone influx rate (Ki). Methods: $[^{18}F]Fluoride$ dynamic PET scans was acquired for 60 min in three normal mini-pigs. The plasma input curve was derived using blood sampling from the femoral artery. Tissue time-activity curves were measured by drawing region of interests (ROls) on the femur head, vertebra, and muscle. Parametric images of Ki were generated using MLAIR and PGA methods. Result: In ROI analysis, estimated Ki values using MLAIR and PGA method was slightly higher than those of NLS, but the results of MLAIR and PGA were equivalent. Patlak slopes (Ki) were changed with different $t^*$ in low uptake region. Compared with PGA, the quality of parametric image was considerably improved using new method. Conclusion: The results showed that the MLAIR was efficient and robust method for the generation of Ki parametric image from $[^{18}F]Fluoride$ PET. It will be also a good alternative to PGA for the radiotracers with irreversible three compartment model.

• Proceedings of the Korean Environmental Health Society Conference
• /
• 2005.12a
• /
• pp.4-15
• /
• 2005

Methylmercury (MeHg) is an environmental pollutant with neurotoxic effects on the central nervous system. The major exposure route of MeHg to humans is via consumption of fish and shellfish which accumulate the chemical through the food web in an aquatic environment. Hair mercury level is an excellent marker for MeHg exposure. We have been conducting a survey on hair mercury contents among general populations from 14 districts to estimate the current Japanese MeHg exposure level. Total mercury levels of all hair samples collected (12923 in total) were analyzed by the oxygen combustion-gold amalgamation method using an atomic absorption mercury detector. Multiple regression analysis revealed that mercury levels were significantly correlated with several covariates, such as sex, age, the amount of daily intake of total fish/shellfish, a preference for certain fish such as tuna or bonito, and artificial waving. The geometric means for the population without artificial waving were 2.47 and 1.65 ${\mu}g/g$ for males (n = 5623) and females (n = 3470), respectively. Hair mercury levels varied with age, and the variations were more significant in males. Since the difference between sexes was not evident at younger ages, some hormonal control might also be involved in the mercury uptake by human hair. The average mercury levels in our hair samples varied among the sampling districts. Tuna is a major carnivorous fish with high mercury accumulations that is often consumed in Japan. The amount of fish consumption and the preference rate far tuna would appear to be responsible far the regional variation in hair mercury levels in Japan. Recently, a provisional tolerable weekly intake (PTWI) of MeHg was revised by 61st JECFA to 1.6 ${\mu}g/kg/week$, which was about half that of the Japanese standard, and corresponded to a hair level of 2.2 ppm. The distribution of hair mercury levels in Japanese populations in the present study indicated that 25% of the Japanese females of child-bearing age were estimated to be exposed to MeHg over the PTWI level. This would reflect the high Japanese consumption of marine products. However, not only mercury contamination, but also the nutritional benefit may have to be considered when discussing the risk involved in the current level of fish and shellfish consumption in Japan.

• The Korean Journal of Applied Statistics
• /
• v.27 no.4
• /
• pp.645-653
• /
• 2014

P-value is the probability of observing a current sample and possibly other samples departing equally or more extremely from the null hypothesis toward postulated alternative hypothesis. When p-value is less than a certain level called ${\alpha}$(= 0:05), researchers claim that the alternative hypothesis is supported empirically. Unfortunately, some findings discovered in that way are not reproducible, partly because the p-value itself is a statistic vulnerable to random variation. Boos and Stefanski (2011) suggests calculating the upper limit of p-value in hypothesis testing, using a bootstrap predictive distribution. To determine the sample size of a replication study, this study proposes thought experiments by simulating boosted bootstrap samples of different sizes from given observations. The method is illustrated for the cases of two-group comparison and multiple linear regression. This study also addresses the reproducibility of the points in the given 95% confidence interval. Numerical examples show that the center point is covered by 95% confidence intervals generated from bootstrap resamples. However, end points are covered with a 50% chance. Hence this study draws the graph of the reproducibility rate for each parameter in the confidence interval.

• Korean journal of food and cookery science
• /
• v.22 no.4 s.94
• /
• pp.495-503
• /
• 2006

The purpose of this study was to analyze the effect of the consumer-brand relationship quality on the brand loyalty in family restaurants. Questionnaires were distributed to 320 students in K University located in Masan, who were sampled by convenience-sampling method. The surveys were conducted from November, 10 to 24, 2005. Of the 287 returned questionnaires, 15 unusable questionnaires were excluded to leave 272 for use in the final analysis(response rate: 85.0%). For the statistical analysis, SPSS(12.0)was used to conduct the descriptive analysis, factor analysis, reliability analysis, correlation and multiple regression analysis. The results of this study showed that 2 constructs (satisfaction and intimacy) of consumer-brand relationship quality have significantly positive effects on the brand loyalty in family restaurants(p<.01). This indicates that as consumer-brand relationship quality strengthens, the customer's brand loyalty increases. In conclusion, food service managers in family restaurants should focus on the marketing strategies to strengthen the quality of consumer-brand relationship in order to increase the brand loyalty of customers.

• Korean Journal of Community Nutrition
• /
• v.11 no.4
• /
• pp.512-519
• /
• 2006

The purpose of this study was to analyze the influence of the consumer-brand relationship quality on the customer satisfaction in the family restaurant. The questionnaires were distributed to 320 students in the K University located in Masan, who were sampled by convenience-sampling method. The surveys were conducted from November 10 to 24, 2005. The 287 questionnaires responded, and 15 unusable questionnaires were excluded, then 272 were used for the final analysis (response rate: 85.0%). For the statistical analysis, SPSS (12.0) was used to conduct the descriptive analysis, factor analysis, reliability analysis, Pearson correlation and multiple regression analysis. The result of this study showed that 2 constructs (trust and intimacy) of consumer-brand relationship quality have significant positive effects on the customer satisfaction in the family restaurant (p < .001). It meant that as consumer-brand relationship quality becomes stronger, the customer satisfaction becomes greater. As a conclusion, the foodservice manager in the family restaurant should focus on the marketing strategy to strengthen the quality of consumer-brand relationship in order to increase the satisfaction of customers.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.24 no.2
• /
• pp.33-40
• /
• 2020

Various studies have been conducted on the structural health monitoring using optical fiber. Optical fibers can be used to measure multiple and distributed strain. Among the optical fiber sensors, FBG sensor has advantages of dynamic response measurement and high precision, but the number of measurement points is limited. Distributed fiber sensors, represented by distributed Brillouin sensors, usually have more than 1000 measurement points, but the low sampling rate makes dynamic measurements impossible. In this study, a hybrid nerve sensor system using only the advantages of the FBG sensor and the distributed Brillouin sensor has been proposed. Laboratory experiments were performed to verify the proposed system, and the accuracy and reproducibility were verified by comparing with commercial sensors. Applying the proposed system, dynamic response ambient measurements are used to evaluate the global state of the structure. When an abnormal condition is detected, the local condition of the structure is evaluated by static response measurement using the distributed measurement system. The proposed system can be used for efficient structural health monitoring.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.34 no.4
• /
• pp.489-495
• /
• 2005

The purpose of this study was to analyze the effect of the consumer-brand relationship Quality (CBRQ) on the brand loyalty in the fast food restaurant in Masan, Korea. The Questionnaires were distributed to 250 students in the K University located in Masan, who were sampled by convenience-sampling method. The surveys were performed from December 6 to 14, 2004. The 246 Questionnaires were responded, and 12 unusable Questionnaires were excluded, then 234 were used for the final analysis $(response rate:\;93.7\%)$. For the statistical analysis, SPSS (12.0) was used to conduct the descriptive analysis, factor analysis, reliability analysis, Pearson correlation and multiple regression analysis. The result of this study showed that 2 constructs (satisfaction and commitment) of consumer-brand relationship Quality have significant positive effects on the brand loyalty in the fast food restaurant. It meant that as consumer-brand relationship quality becomes stronger, the customer's brand loyalty becomes greater. The differences of customer loyalty between the high and low group of self-connective attachment, satisfaction, commitment, trust and intimacy were significant. So the brand loyalty of high group of customer-brand relationship quality was significantly higher than that of low group of customer-brand relationship quality. As a conclusion, the operator in the fast food restaurant should focus on the marketing strategy to strengthen the quality of consumer-brand relationship in order to increase the brand loyalty of customers.

• Korean Journal of Social Welfare
• /
• v.52
• /
• pp.273-299
• /
• 2003

Children in one-parent families have difficulties from negative perception and prejudice in society in spite of increasing divorce rate and the substantial number of one-parent families. This research aims to provide basic setting-up materials of the equal educational environment to children in one-parent families by examining teachers' perception and attitudes towards those children, and also analysing which factors are associated with the teachers' perceptions and attitudes. In particular, by exploring teachers' internalized value system and stereotyped conception are closely related to the process of evaluating children's personality and behavior, this research suggests that social consciousness to one-parent families should be changed and improved in terms of equality. According to the research result, most teachers notice that children in one-parent families are increasing by number at schools, however, they do not seem to understand properly children's situations including psychological condition. Teachers' negative perception of children in one-parent families are not only influenced by teachers' socio-demographic characteristics, experience factors and children's school life, but also by teachers' own personal value of familism and divorce. Such teachers' attitudes towards one-parent family children are easily predicted to influence children's confidentiality and self-respect. Therefore, it is proposed that the change of social consciousness on one-parent families, the change of educational system and educational environment, development of educational training program for teachers, allocation of school social worker or school counsellor, and empowerment of one-parent family are necessary in order children in one-parent families to have more equitable opportunities at school.

• Asian Pacific Journal of Cancer Prevention
• /
• v.17 no.12
• /
• pp.5295-5302
• /
• 2016

Objectives: A physically active lifestyle is important for cancer survivors. Therefore, this study was conducted to 1) provide population-based estimates of the prevalence of physical activity and sitting time, and 2) their correlates in Korean cancer survivors. Materials and Methods: This study analyzed a cancer survivor subsample (N=1,482) from 2008-2013 Korea National Health and Nutrition Examination Survey (KNHANES), data selected with a complex sampling design. Overall and subgroup-specific prevalences of physical activity and sitting time were estimated. Correlates of moderate- to vigorous-intensity physical activity ( MVPA) and sitting time were tested using age-group-specific hierarchical multiple regression models. Results: Overall adherence rate to physical activity guidelines was 34.9% (95% CI=31.5-38.4). Age-group-specific adherence rates were 41.1% (95% CI=36.3-45.9) in adults (30-64 years old), and 25.3% (95% CI=21.0-25.3) in older adults (65 years or older). Adults spent 213.33 minutes (95% CI=172.4-254.3) per week on MVPA and 55.3 minutes (95% CI=36.4-64.6) on sitting time per day. In adults, sitting time was significantly associated with employed status (B=28.0, p=0.046), smoking (B=-47.4, p=0.020), and number of comorbidity conditions (B=-13, p=.037). MVPA was significantly associated with marital status (B=134.9, p<0.001), employment status (B=98.12, p=.046), and years since cancer diagnosis (B=104.7, p=0.015). Older adults spent 162.2 minutes (95% CI=119.5-204.8) per week on MVPA and 63.0 minutes (95% CI=45.0-89.5) on sitting time per day. Their significant correlates were sex (B= -45.2, p=0.014), smoking (B=-70.14, p<0.001), and years since cancer diagnosis (B=37.0, p=0.024). Age (B=5.8, p=0.042) and marital status (B=83.8, p=0.033) were also significantly associated with MVPA in older adults. Conclusion: A majority of Korean cancer survivors do not sufficiently participate in physical activity. In general, older, unhealthier, non-working, and being unmarried were risk factors for physical inactivity. While this study informs public health policy makers and practitioners about physical activity intervention demand for cancer survivors, future investigations should address psychosocial mediators to better inform intervention programs.

• Journal of the Korean Society of School Health
• /
• v.34 no.3
• /
• pp.133-150
• /
• 2021

Purpose: The epidemiologic understanding of allergic diseases, including prevalence and risk factors, is needed for allergy management. This study identified the prevalence of and coping patterns for various types of allergies, such as asthma, allergic rhinitis (AR), atopic dermatitis (AD), allergic conjunctivitis (AC), food allergy (FA), and drug allergy (DA), in Nam-gu, Ulsan, one of the most industrialized districts in Korea. Methods: A cross-sectional study was performed using a self-report multiple choice questionnaire. The International Study of Asthma and Allergies in Childhood (ISAAC) and other measures were reviewed to develop the questionnaire. Data was collected from May 9th to November 30th of 2018. Descriptive and frequency analyses were performed to apprehend the prevalence of symptoms, diagnostic rates, diagnosis dates, treatment history, and others. Results: By randomized sampling, 9,102 children from 25 nurseries, 25 kindergartens, and 15 elementary schools participated in the study. The prevalence of asthma, AR, AD, AC, FA, and DA were 11.1%, 48.7%, 15.5%, 17.6%, 15.1%, and 2.0%, respectively. The respective rate of ever being diagnosed with asthma, AR, AD, AC, FA, and DA were 4.2%, 38.4%, 25.5%, 23.3%, 9.7%, and 1.1%, respectively. Last year's allergy related school absenteeism rates were 10.8%, 4.1%, and 1.3% for asthma, AR, and AD, respectively. Lastly, 59.2% of the participants considered air pollution as the most challenging factor in allergy management. Conclusion: This study comprehensively investigated the current state of various allergic diseases in Nam-gu, Ulsan. The study's findings are expected to be applied to strategies for decreasing the socioeconomic burden of allergic diseases.