• Safety and Health at Work
• /
• v.2 no.2
• /
• pp.176-182
• /
• 2011

Objectives: Previous investigations have presented some evidence of late cognitive effects in dental personnel exposed to metallic mercury. We wanted to examine if Norwegian dentists have an increased prevalence of symptoms consistent with neurological and/or cognitive malfunction. Methods: The study group consisted of 406 dentists from central Norway and 217 controls from the general population, all under the age of 70. They had responded to a standardised postal questionnaire (Euroquest) inquiring about seven symptoms in regard to neurology, psychosomatics, memory, concentration, mood, sleep disturbances, and fatigue. A score was calculated for each symptom based on 4 to 15 single questions scored on a scale from 1 (seldom or never) to 4 (very often). Results: The dentists and controls had a participation rate of 57.2 % and 42.9 % respectively. The dentists reported no more cognitive symptoms than the controls, with low average symptom scores from 1.16 for neurological symptoms in males to 1.73 for fatigue in females. Corresponding figures for the controls were 1.22 and 1.77. There were a total of 1.2 % of the dentists and 1.8 % of the controls who reported having three or more of the seven symptoms "often" or more frequently. Conclusion: Norwegian dentists do not report more cognitive and neurological symptoms than controls from the general population.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
• /
• 2000.06a
• /
• pp.1-10
• /
• 2000

The development of paper machines, increasing machine speeds with new, mostly low basis weight and/or high ash content paper grades, as well as the fact that several trends regarding process items have increased the sensitivity of papermaking. At the same time, papermakers are looking for flexibility in the production line. We can say that with all PMs the biggest benefits with the lowest capital spending can be achieved by focusing on improved wet end management. In order to manage wet end chemistry on a paper machine, our goal is to control sub-process through which we can influence the operation of the entire wet end with maximum effect. Key measurements and controls are-white water consistency control which is the most effective way to control retention - charge demand measurement and control which takes care of concentration of the anionic material entering to PM -ash measurements and controls which are deeply related to retention and paper quality This paper presents and concentrates to two of these key controls ; retention and charge. The purpose of charge control is to give the process control the tools to react to changes caused by amount of dissolved and colloida material incoming to wet end system. It is called coagulation or fixing control. Retention control is then taking care of retention aid flow to the process by responding any changes seen in white water consistency. It is called flocculation control. Each of these solutions separately , and even more effectively all together, stabilize the wet end operations and so greatly improve the produced paper quality and machine runnability. Practical results will be presented and they are referring to the latest mill cases. We have developed the first wet end measuring system in the late 1980s and control solutions based on this modern measuring technology were completely updated in 1990s. This paper introduces the principle, operation , and results of our unique wet end analyzers (retention and charge ) which are at the level of automation solutions as a part of paper machine quality control Especially our newest member of the platform , on-line charge analyzer has reached and set new standards to the on-line charge monitoring.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.32 no.5
• /
• pp.44-53
• /
• 2000

The development of paper machines, increasing machine speeds with new, mostly low basis weight and/or high ash content paper grades, as well as the fact that several trends regarding process items have increased the sensitivity of papermaking. At the same time, papermakers are looking for flexibility in the production line. We can say that with all PMs, the biggest benefits with the lowest capital spending can be achieved by focusing on improved wet end management. In order to manage wet end chemistry on a paper machine, our goal is to control subprocesses through which we can influence the operation of the entire wet end with maximum effect. Key measurements and controls are - white water consistency control which is the most effective way to control retention. - charge demand measurement and control which takes care of concentration of the anionic material entering to PM. - ash measurements and controls which are deeply related to retention and paper quality. This paper presents and concentrates to two of these key controls: retention and charge. The purpose of charge control is to give the process control the tools to react to changes caused by amount of dissolved and colloidal material incoming to wet end system. It is called coagulation or fixing control. Retention control is then taking care of retention aid flow to the process by responding any changes seen in white water consistency. It is called flocculation control. Each of these solutions separately, and even more effectively all together, stabilize the wet end operations and so greatly improve the produced paper quality and machine runnability. Practical results will be presented and they are referring to the latest mill cases. We have developed the first wet end measuring system in the late 1980s and control solutions based on this modern measuring technology were completely updated in 1990s. This paper introduces the principle, operation, and results of our unique wet end analyzers (retention and charge) which are at the level of automation solutions as a part of paper machine quality control. Especially our newest member of the platform, on-line charge analyzer has reached and set new standards to the on-line charge monitoring.

• Journal of Cardiovascular Imaging
• /
• v.26 no.4
• /
• pp.201-213
• /
• 2018

BACKGROUND: Children with significant adenotonsillar hypertrophy (ATH) may show right ventricular (RV) dysfunction. We aimed to evaluate RV dysfunction in such children before adenotonsillectomy by evaluating peak longitudinal right atrial (RA) strain (PLRAS) in systole. PLRAS, electrocardiogram (ECG) and conventional echocardiographic parameters were compared to distinguish children with significant ATH with sleep-related breathing disorder (ATH-SRBD) from controls. METHODS: Fifty-six children (23 controls and 33 children with ATH-SRBD without symptoms of heart failure) were retrospectively studied. Preoperative echocardiograms and ECGs of children with ATH-SRBD who underwent adenotonsillectomy were compared to those of controls. Available postoperative ECGs and echocardiograms were also analyzed. RESULTS: Preoperatively, prolonged maximum P-wave duration (Pmax) and P-wave dispersion (PWD), decreased PLRAS, and increased tricuspid annulus E/E' were found in children with ATH-SRBD compared to those of controls. From the receiver operating characteristic curves, PLRAS was not inferior compared to tricuspid annulus E/E', Pmax, and PWD in differentiating children with ATH-SRBD from controls; however, the discriminative abilities of all four parameters were poor. In children who underwent adenotonsillectomy, echocardiograms $1.2{\pm}0.4$ years after adenotonsillectomy showed no difference in postoperative PLRAS and tricuspid annulus E/E' when compared with those of the preoperative period. CONCLUSIONS: Impaired RA deformation was reflected as decreased PLRAS in children with ATH-SRBD before adenotonsillectomy. Decreased PLRAS in these children may indicate subtle RV dysfunction and increased proarrhythmic risk. However, usefulness of PLRAS as an individual parameter in differentiating preoperative children with ATH-SRBD from controls was limited, similar to those of tricuspid annulus E/E', Pmax, and PWD.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.19
• /
• pp.8413-8422
• /
• 2014

Background: To investigate the relationship of five TP53 polymorphisms (p.P47S, p.R72P, PIN3 ins16bp, p.R213R and r.13494g>a) with the esophageal cancer (EC) risk in North Indians. Materials and Methods: Genotyping of p.P47S, p.R72P, PIN3 ins16bp, p.R213R and r.13494g>a polymorphisms of TP53 in 136 sporadic EC patients and 136 controls using polymerase chain reaction and PCR-RFLP. Results: The frequencies of genotype RR, RP and PP of p.R72P polymorphism were 16.91 vs 26.47%, 58.82 vs 49.27% and 24.27 vs 24.27% among patients and controls respectively. We observed significantly increased frequency of RP genotype in cases as compared to controls (OR=1.87, 95% CI, 1.01-3.46, p=0.05). The frequencies of genotype A1A1, A1A2 and A2A2 of PIN3 ins16bp polymorphism were 69.12 vs 70.59%, 27.20 vs 25% and 3.68 vs 4.41% among patients and controls. There was no significant difference among genotype and allele distribution between patients and controls. The frequencies of genotype GG, GA and AA of r.13494g>a polymorphism were 62.50 vs 64.70%, 34.56 vs 30.15% and 2.94 vs 5.15% among patients and controls respectively. No significant difference between genotype and allele frequency was observed in the patients and controls. For p.P47S and p.R213R polymorphisms, all the cases and controls had homozygous wild type genotype. The RP-A1A1-GG genotype combination shows significant risk for EC (OR=2.01, 95%CI: 1.01-3.99, p=0.05). Conclusions: Among the five TP53 polymorphisms investigated, only p.R72P polymorphism may contributes to EC susceptibility.

• Journal of the Ergonomics Society of Korea
• /
• v.35 no.1
• /
• pp.11-27
• /
• 2016

Objective: The purpose of this study was to develop and evaluate high technology adaptive driving controls, such as mini steering wheel-lever system and joystick system, for the people with physical disabilities in the driving simulator. Background: The drivers with severe physical disabilities have problems in operation of the motor vehicle because of reduced muscle strength and limited range of motion. Therefore, if the remote control system with driver-by-wire technology is used for adaptive driving controls for people with physical limitations, the disabled people can improve their quality of life by driving a motor vehicle. Method: We developed the remotely controlled driving simulator with drive-by-wire technology, e.g., mini steering wheel-lever system and joystick system, in order to evaluate driving performance in a safe environment for people with severe physical disabilities. STISim Drive 3 software was used for driving test and the customized Labview program was used in order to control the servomotors and the adaptive driving devices. Thirty subjects participated in the study to evaluate driving performance associated with three different driving controls: conventional driving control, mini steering wheel-lever controls and joystick controls. We analyzed the driving performance in three different courses: straight lane course for acceleration and braking performance, a curved course for steering performance, and intersections for coupled performance. Results: The mini steering wheel-lever system and joystick system developed in this study showed no significant statistical difference (p>0.05) compared to the conventional driving system in the acceleration performance (specified speed travel time, average speed when passing on the right), steering performance (lane departure at the slow curved road, high-speed curved road and the intersection), and braking performance (brake reaction time). However, conventional driving system showed significant statistical difference (p<0.05) compared to the mini steering wheel-lever system or joystick system in the heading angle of the vehicle at the completion point of intersection and the passing speed of the vehicle at left turning. Characteristics of the subjects were found to give a significant effect (p<0.05) on the driving performance, except for the braking reaction time (p>0.05). The subjects with physical disabilities showed a tendency of relatively slow acceleration (p<0.05) at the straight lane course and intersection. The steering performance and braking performance were confirmed that there was no statistically significant difference (p>0.05) according to the characteristics of the subjects. Conclusion: The driving performance with mini steering wheel-lever system and joystick control system showed no significant statistical difference compared to conventional system in the driving simulator. Application: This study can be used to design primary controls with driver-by-wire technology for adaptive vehicle and to improve their community mobility for people with severe physical disabilities.

• Journal of Preventive Medicine and Public Health
• /
• v.14 no.1
• /
• pp.111-116
• /
• 1981

Economic development of Korea brought rapid progress and expansion of her industries. Accordingly, number of workers who have been exposed to hazardous metals are increasing. For better understanding the significance of on the job human metal pollution, a total of 22 solderers among autoworkers and 28 controls among medical students was purposively selected as samples of the study. From their blood, concentrations of cadmium and lead were measured with atomic absorption spectrophotometer, and to compare with statistical indices of controls those of solderers were sumarized as follows. 1. Each frequency distribution of cadmium and lead concentration in blood of solderers was more positively skewed showing non-Gausian distribution. 2. Interindividual variation of lead concentration in blood of solderers was markedly revealed. 3. Each mean of cadmium and lead concentration in blood of solderers was higher than that of controls(Cd;p<0.01, Pb;p<0.01). 4. Relative ratio of cadmium concentration in blood of solderers to that of controls was 1.36 by arithmatic mean and 1.39 by geometric mean. Relative ratio of lead concentration in blood of solderers to that of controls was 1.53 by arithmatic mean and 1.30 by geometric mean. 5. It was shown that concentration of lead is slightly correlated with that of cadmium both in solderers and controls(solderers; p<0.1, controls;p<0.1).

• 대한예방의학회:학술대회논문집
• /
• 1994.02b
• /
• pp.265-269
• /
• 1994

A brief review is presented of the strengths and weaknesses of historical controls, data banks, and randomized trials in the evaluation of clinical treatment. Use of pre randomized versus postrandomized informed consent is discussed. Recommendations are made for the development of an appropriate clinical research strategy.

• Journal of the Korean Society for Industrial and Applied Mathematics
• /
• v.7 no.2
• /
• pp.23-34
• /
• 2003

In this paper we establish a set of sufficient conditions for the controllability of perturbed integrodifferential systems with prescribed controls by using the Schaefer fixed point theorem.

• Korean Journal of Occupational Health Nursing
• /
• v.4
• /
• pp.84-101
• /
• 1995

The periodic health examination have been shown the important role on early detection, early treatment and prevention of disease. Until now, there have been many studies that showed the effectiveness of the periodic health examination on the early detection and early treatment of disease to some extent. But there are few studies about primary prevention before health problem arise. In this case-control study, 29 newly detected hypertensive cases, 31 liver disease cases and 65 controls which are all available for 6-year data in the periodic health examination of a occupational field were compared to investigate the significant increase trend of health status between the groups. The results will be used for the occupational health nurses to provide appropriate primary prevention to the employees. The hypertensive and liver disease cases were divided observation-needed group and treatment-needed group. The data on systolic blood pressure, diastolic blood pressure, Body Mass Index and Broca Index in hypertensive cases and SGOT, SGPT, Body Mass Index and Broca Index in liver disease cases were analyzed by t-test and ANOVA. The specific findings are summarized as follows. 1. In the comparison between the hypertensive cases and controls, SBP and DBP of the observation-needed group and the treatment-needed group were significantly higher than the data of the controls for past 6 years. It was 2-3 years ago showing increase over 140/90mmHg of blood pressure in the hypertensive cases before they are categorized as hypertensive cases. In the observation-needed group and the treatment-needed group, the trend of the blood pressure for 6 years were significantly higher than the one of the controls. 2. In the comparison between the liver disease cases and controls, SGOT and SGPT of the observation-needed group and the treatment-needed group were significantly higher than the data of the controls for past 6 years. It was 2 years ago showing increase within upper normal limit of SGOT and 5 years ago of SGPT in the liver disease cases before they are categorized as liver disease cases. In the observation-needed group and the treatment-needed group, the trend of the liver enzyme for 6 years were significantly higher than the one of the controls. With these results, the author proposed that intervention for the primary prevention such as continuous follow-up, health education and weight control to the population who has over 140/90mmHg of blood pressure and upper normal limit of AST and ALT.