• Journal of Preventive Medicine and Public Health
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• v.29 no.4 s.55
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• pp.863-875
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• 1996

In order to prepare the fundamental data for the health promotion by assessing the exposure level of styrene, the author determined the concentration of mandelic acid and phenylglyoxylic acid in urine of 42 workers who were exposed to styrene by high performance liquid chromatography and surveyed 16 symptoms, by questionnaire and also tested neurobehavioral test(digit symbol, benton visual retention) in 2 FRP plants of Kyung Nam area from July to September, 1995. Control was sampled by age sex matching method. The concentration of styrene in air was determined by gas chromatography. The results were as follows; 1. Geometric mean concentration of styrene in air was 17.4ppm, geometric mean concentration of mandelic acid(MA) in urine were 404.3mg/g creatinine for exposure group, 46.4mg/g creatinine for control group, geometric mean concentration of phenylglyoxylic acid(PGA) in urine were 57.5mg/g creatinine for exposure group, 9.5mg/g creatinine for control group. Mean concentration of MA and PGA showed statistically significant difference between exposure group and control group(p<0.01). 2. Number of symptom were 2.9 for exposure group, 3.3 for control group, number of digit symbol were 24.1 for exposure group, 32.5 for control group, number of Benton visual retention test were 6.1 for exposure group, 6.0 for control group, respectively. As result of adjusting the education year, number of Benton visual retention test showed statistically significant difference between exposure group and control group(p<0.05). 3. Excellent correlation were observed between environmental styrene exposure and urinary MA(r=0.80), PGA(r=0.73), and MA+PGA(r=0.81).

• Journal of the Korean Society of Safety
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• v.21 no.4 s.76
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• pp.25-32
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• 2006

LonWorks over IP(LonWorks-IP) virtual device network(VDN) is an integrated form of LonWorks device network and IP data network. In especially real-time distributed servo applications on the factory floor, timely response is essential for predictive and preventive maintenance. The time delay in servo control on LonWorks-IP based VDN has highly stochastic nature. LonWorks-IP based VDN induced transmission delay deteriorates the performance and stability of the real-time distributed control system and can't give an effective preventive and predictive maintenance. In order to guarantee the stability and performance of the system, and give an effective preventive and predictive maintenance, LonWorks-IP based VDN induced time-varying uncertain time delay needs to be predicted and compensated. In this paper new Pill control scheme based on Smith predictor, disturbance observer and band pass filter is proposed and tested through computer simulation about position control of DC servo motor. It is shown that how can the proposed control scheme be designed to minimize the effects of uncertain varying time delay and model uncertainties. The validity of the proposed control scheme is compared and demonstrated with the comparison of internal model controllers(IMC) based on Smith predictor with and without disturbance observer.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.51 no.6
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• pp.262-268
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• 2002

Preventive control has to solve two important problems. The first is fast and accurate severity assessment of instability originated from the occurrence of a dangerous contingency. The second is to choose an action able to stabilize it. In this paper we assess contingencies in power systems using PASF(Power Angle Shape Filtering) and control power systems by a generation rescheduling. The control action stabilize the whole set of harmful contingencies simultaneously. Note that conventional time-domain transient stability methods can hardly tackle preventive control. So, we study the preventive control using off-line method. The proposed method is applied to prevent and to correct loss of synchronism of all the generators in a operating systems data.

• Smart Structures and Systems
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• v.15 no.3
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• pp.609-625
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• 2015

Management of infrastructure stock is essential in sustainability of society, and its analysis and optimization are studied in the light of control system modeling in this paper. At the first part of the paper, cost of stock management is analyzed based on macroscopic statistics on infrastructure stock and economical growth. Stock management burden relative to economy is observed to become larger at low economic growth periods in developed economies. Then, control system modeling of stock management is introduced and by augmenting maintenance actions as control input, dynamic behavior of stock is simulated and compared with existing time history statistics. Assuming steady state conditions, applicability of the model to cross sectional data is also demonstrated. The proposed model is enhanced so that both preventive and corrective maintenance can be included as system inputs, i.e., feedforward and feedback control inputs. Optimal management strategy to achieve specified deteriorated stock level with minimal cost, expressed in terms of preventive and corrective maintenance actions, is derived based on estimated parameter values for corrosion of steel bridges. Relative cost effectiveness of preventive maintenance is shown when target deteriorated stock level is lower.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.8
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• pp.4999-5008
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• 2014

This study was conducted to identify the factors related to the cancer preventive behaviors of middle aged women. The data was collected from October $1^{st}$ 2012 to February $10^{th}$ 2013 from 114 middle aged women in four churches in B city. As a result, there were significant differences in the cancer preventive behaviors according to cancer preventive education, concerns about cancer information and the utilization of cancer information. The cancer preventive behaviors were weakly related to the internal health locus of the control, chance health locus of the control and self-esteem. In addition, there was moderate correlation between the cancer preventive behaviors and the external health locus of the control. Meaningful variables that explain the cancer preventive behaviors were the external health locus of the control, self-esteem, cancer preventive education in that order. The total explanation power was 25.3% and the external health locus of the control has most explanation power. In conclusion, it is necessary to develop nursing intervention and health education for middle aged women to raise the internal health locus of the control and self-esteem, and encourage attending cancer preventive education to improve the preventive behaviors against cancer.

• Journal of Korean Dental Science
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• v.7 no.2
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• pp.87-93
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• 2014

Purpose: The objective of this study was to evaluate the caries prevention effect of school-based fluoride mouth rinsing (FMR) program implemented in the Hanuul district of Mongolia, which has a very low socioeconomic status and extremely poor infrastructure for oral health. Materials and Methods: One hundred and seventy children aged from 6 to 8 years of the FMR school and 187 children aged from 6 to 8 years of the control school completed the baseline survey. Children from the FMR school rinsed with 0.05% sodium fluoride everyday under supervision, while those from the control school did not. Adjusted caries preventive fraction (CPF) for 2 years were calculated to evaluate the effect of the FMR program. Result: After 2 years, 288 schoolchildren remained in the study. Decayed, missing or filled permanent teeth (DMFT) and index of the FMR and the control schools at baseline were 0.11 and 0.12, respectively, and the average DMFT increment of the FMR and the control schools after 2 years were 0.35 and 0.65, respectively. The adjusted CPF of DMFT was 48.5%. Conclusion: These findings show that a school-based FMR is an effective caries preventive program in a socially deprived community with poor infrastructure for oral health.

• Journal of Preventive Medicine and Public Health
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• v.36 no.3
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• pp.263-270
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• 2003

Objectives : To identify the factors related to awareness, treatment, and control of hypertension in a Gwacheen population. Methods : This study surveyed 1,176 Gwacheon residents older than 40 years, and measured blood pressure using a standardized guideline in 1999. The study subjects were 473 adults (175 males, 295 females) with hypertension defined as a systolic blood pressure $\geq$140 mmHg, diastolic blood pressure $\geq$90 mmHg or reported treatment with antihypertensive medication. Information on awareness, treatment, and control of hypertension, and sociodemographic and health-related factors .was collected through person-to-person interviews with a structured questionnaire. Results : Overall, 252 (53.3%) of hypertensive subjects were aware of their condition, of whom as many as 193 (76.6%) were being treated, and 81 (42.0%) had their blood pressure controlled at the recommended level (<140/90 mmHg). However, of the 473 subjects found to have hypertension, only 40.8% were being treated, and 17.1% were under control. There were no significant differences in the proportions of awareness, treatment, and control of hypertension. In multiple logistic regression models, awareness of hypertension was positively associated with age and family history of hypertension in females. Control of hypertension was also positively associated with haying a partner and marital status in females.. Conclusion : These findings demonstrate that much greater efforts on improving awareness, treatment, and control of hypertension are needed, even in urban community settings, considering related factors such as a9e, family history, and marital status. However, these factors should be further investigated for their causal relationship.

• Journal of Dental Anesthesia and Pain Medicine
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• v.23 no.6
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• pp.303-315
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• 2023

Painless treatment determines the quality of pediatric dental care. Although local anesthesia has been used to manage pain in dentistry, children often cite traditional aspirating syringes as a symbol of fear and pain. Adequate pain control during dental procedures may help alleviate fear and anxiety and instill positive oral health attitudes in children. Newer approaches such as intranasal spray, centbucridine, jet injectors, buzzy devices, and acupressure have been developed to help dentists provide near-painless injections while reducing dental anxiety. This review aims to summarize newer approaches to alleviate pain and anxiety in children.

• Research in Community and Public Health Nursing
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• v.28 no.3
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• pp.260-270
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• 2017

Purpose: The purpose of this study was to examine the effects of the motivational interviewing (MI) dementia preventive intervention on dementia preventive behaviors, depression and cognitive function among elderly over 75 years of age in nursing homes. Methods: A nonequivalent control group pretest-posttest design was used. A total of 57 participants were divided into three groups; 18 in the MI dementia preventive intervention (Group A), 20 in the dementia preventive program (Group B) and 19 in the control group. Dementia preventive behaviors, depression, and cognitive function were assessed at pre, post, and 1 month after the intervention. Data were analyzed using descriptive statistics, t-test, ANOVA and repeated measure ANOVA. Results: The results reported that there were significant differences in dementia preventive behaviors and depression among Group A, B, and C. Also, there were significant differences in dementia preventive behaviors and cognitive function during time periods. There was a significant interaction between groups and times in relation to depression. Results suggested that the effects of MI dementia preventive program was persistent after 1 month following the intervention. Conclusion: Further research needs to develop dementia preventive programs considering physical and mental traits of the elderly in late years staying at nursing homes.

• Nutritional Sciences
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• v.5 no.3
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• pp.155-160
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• 2002

The purpose of this study was to investigate the effects of micronutrient supplementation on the growth of preschool children in China. A double-blind, placebo-controlled trial was conducted on 156 growth retarded preschool children who were randomly assigned to the following five groups : supplemental control (S-control; n=28); zinc supplementation (＋Zn; 3.5mg Zn/day, n=34); zinc and calcium supplementation (＋ZnCa; 3.5mg Zn ＋ 250mg Ca/day, n=37); zinc, calcium and vitamin A supplementation (＋ZnCaVA; 3.5mgZn ＋ 250mgCa ＋ 200gVA/day, n=28); and calcium and vitamin A supplementation (＋CaVA; 250mgCa ＋ 200gVA/day, n=29). Another 34 children of normal height were selected as a normal control (N-control). Supplementation continued for twelve months. After supplementation, the height gains in the ＋Zn group (7.84cm per year) and the ＋ZnCa group (7.70 cm per year) were significantly higher than that in the S-control group (6.74 cm per year, P＜0.05). The weight gain in the ＋ZnCaVA group (2.55kg per year) and the ＋CaVA group (2.57 kg per year) was also significantly higher than that in the S-control group (2.19 kg per year, P＜0.05). The average number of days of illness in each group taking supplements was lower than that in the S-control group (13 days per year compared with 23 days per year). No significant differences in bone maturity were observed between the groups. In conclusion, in this study Zinc and Zinc ＋ Calcium supplementation improved the height gain, and vitamin A improved the weight gain, in growth retarded preschool children, but these supplements did not affect the maturity of bone. Micronutrient supplementation also lowered the morbidity of these children.