• Journal of the Ergonomics Society of Korea
• /
• v.32 no.4
• /
• pp.381-387
• /
• 2013

Objective: This paper studies the method of measuring whole-body vibration in the car and terms associated. Background: Human exposure to vibration can be broadly classified as localized and whole-body vibration. The whole-body vibration affects the entire body of the exposed person. It is mainly transmitted through the seat surfaces, backrests, and through the floor to an individual sitting in the vehicle. It can affect the comfort, performance, and health of individuals. Method: Human responses to whole-body vibration can be evaluated by two main standards such as ISO 2631 and BS 6841. The vibration is measured at 8 axes - three translations at feet, 3 translations of hip and two translations of back proposed by Griffin. B&K's sensors used in this study are the 3-axes translational acceleration sensor to measure the translational accelerations at the hip, back and foot. Results: The parameters associated with the whole-body vibration in the car are frequency weightings, frequency weighted root-mean-square, vibration dose values, maximum transient vibration value, seat effective amplitude transmissibility, ride values and ride comfort. Conclusion: Studied the evaluating methods of vibration exposure and ride comfort. Application: Evaluation of whole-body vibration in the car.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.15 no.3
• /
• pp.291-300
• /
• 2004

Due to the rapid growth of mobile communication services, many studies have been performed on the biological effects of EMF(Electromagnetic field) exposure. However, it is not easy to create the field uniformity in radio frequency. To overcome this difficulty, the electric field and SAR(Specific Absorption Rate) distribution is developed to measure the whole body exposure system. In this paper, we developed the whole body exposure system for in-vivo study utilizing reverberation chamber which has a high possibility of practical use by substituting previous the EMC chamber. The field uniformity in the test area of the designed reverberation chamber was satisfied by the simulation and measurement data. In animal study of the whole body exposure for a mouse, the results of FDTD simulation were compared with those of measurement to confirm SAR under the electromagnetic exposure. We analyze the electric field distribution in the interior of the reverberation chamber and treat these results in statistical manner. In the CDMA frequency band(PCS ＆ Cellular band), an average value of the whole body SAR and local peak value for a experimental mouse were presented for various input power.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.15 no.12 s.105
• /
• pp.1327-1331
• /
• 2005

This Paper addresses what amount of whole-body vibration is exposed to Korean pilots of UH60 helicopters during their mission flight. To measure the expose4 whole-body vibration, the 12-axis whole-body vibration measurement system was used. It enables the direct measurement of whole-body vibration exposed from the body contact area consisting of the feet, hip and back. The measured 12-axis vibration signals were used to evaluate the vibration comfort level experienced by the pilots of UH60 helicopters. The evaluated vibration comfort level is found to be closeto 0.74-0.79m/s, which is equivalent to the semantic scale of 'fairly uncomfortable'. To assess the health effects of whole-body vibration exposed to Korean pilots of UH60 helicopters during their mission flight, the rms-based and VDV(vibration dose value)-based evaluation schemes, recommended by ISO 2631-1:1977, were exploited in this work. The evaluated results indicate that Korean pilots cannot avoid the fatigue-decreased proficiency limit after two-hour continuous flight. The whole-body vibration level exposed from the UH60 helicopters during continuous 10-hours mission flight is found to reach to the vibration exposure limit.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2005.05a
• /
• pp.132-137
• /
• 2005

This paper addresses what amount of whole-body vibration is exposed to pilots of UH60 helicopters during flight. To measure the whole-body exposed from the feet and seat, the 12-axis vibration measurement system was used. It enables simultaneous measurement of vibration exposure from the body contact area of the feet, hip and back. The measured 12-axis vibration signals are exploited to the comfort level of UH60 helicopters during flight. It is shown that the evaluated ride value is close to $0.74{\sim}0.79m/s^2$ and that it is equivalent to the semantic scale of 'fairly uncomfortable'. To assess the health effects of whole-body vibration exposed to pilots of UH60 helicopters during their flight, the rms-based and VDV(vibration dose value)-based evaluation results of measured four-axis vibration signals are shown in this work. The fatigue-decreased proficiency limit, whose level is half of the exposure limit, is expected to come after the two-hour flight. The exposure limit is shown to reach after the 10-hour flight.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.16 no.6
• /
• pp.1211-1216
• /
• 2002

To evaluate whole-body vibration(WBV) exposure and fatigue-decreased proficiency(FDP) boundary in passenger car driver, several roads in Busan were divided into 3 types by the condition of road surface; Road 1 was partially damaged, Road 2 was normal without damage, and Road 3 was better than Road 2. The results were following: The highest passenger driver's exposures to whole-body vibration acceleration and fatigue-decreased proficiency boundary at 40km/h were 0.108m/s² and about 2099 minutes in Road 2 for xh axis, 0.134m/s² and about 1585 minutes in Road 2 for yh axis, and 0.183m/s² and about 1053 minutes in Road 2 for zh axis, respectively. The highest passenger driver's exposures to whole-body vibration acceleration and fatigue-decreased proficiency boundary at 80km/h were 0.219m/s² and about 830 minutes in Road 3 xh axis, 0.203m/s² and about 918 minutes in Road 3 for yh axis, and 0.622m/s² and about 195 minutes in Road 1 for zh axis, respectively. The highest vector sums of whole-body vibration exposure at 40km/h and 804km/h were 0.328m/s² in Road 2 and 0.730m/s² in Road 1, respectively. The highest crest factors at 40km/h were 4.25 in Road 1 for xh, 4.51 in Road 3 for yh, and 5.81 in Road 2 for zh, respectively. The highest crest factors at 80km/h were 5.57 in Road 1 for xh, 5.60 in Road 2 for yh, and 6.46 in Road 3 for zh, respectively. The highest transmissibilities of whole-body vibration from floor to seat at 40km/h and 80km/h were 0.89 in Road 3 and 0.82 in Road 3 for xh axis, 0.83 in Road 3 and 0.87 in Road 1 and 2 for yh, and 0.80 in Road 2 and 0.92 in Road 1 tor zh axis, respectively. The highest fatigue-decreased proficiency boundaries for whole-body vibration exposure of passenger car driver in floor and seat were 457 minutes in Road 3 and 583 minutes in Road 3 at 40km/h and 159 minutes in Road 2 and 251 minutes in Road 2 at 80km/h, respectively.

• Safety and Health at Work
• /
• v.13 no.1
• /
• pp.73-77
• /
• 2022

Background: Whole-body vibration (WBV) exposure of coal mine dumper operators poses numerous health hazards. The case-control study was aimed at assessing the relative musculoskeletal health risk of dumper operators' exposure to WBV with reference to the nonexposed group. Methods: Measurements of WBV exposure were taken at the operator-seat interface using a human vibration analyzer for 110 dumper operators in three coal mines. This vibration measurement was supplemented by a questionnaire survey of 110 dumper operators exposed to WBV and an equal number of workers not exposed to WBV. The relative risk of musculoskeletal disorders (MSDs) has been assessed through the case-control study design. Results: ISO guidelines were used to compare the health risk. It was observed that the prevalence of pain in the lower back was 2.52 times more in the case group compared to the control group. The case group of Mine-2 was 2.0 times more prone to vibration hazards as compared to Mine-3. Conclusion: The case group is more vulnerable to MSDs than the control group. The on-site measurement as well as the response of the dumper operators during the questionnaire survey corroborates this finding.

• Toxicological Research
• /
• v.33 no.2
• /
• pp.165-171
• /
• 2017

Bisphenol A (BPA) is a monomer used in a polymerization reaction in the production of polycarbonate plastics. It has been used in many consumer products, including plastics, polyvinyl chloride, food packaging, dental sealants, and thermal receipts. However, there is little information available on the inhalation toxicity of BPA. Therefore, the aim of this study was to determine its inhalation toxicity and effects on the estrous cycle, spatial learning, and memory. Sprague-Dawley rats were exposed to 0, 10, 30, and $90mg/m^3$ BPA, 6 hr/day, 5 days/week for 8 weeks via whole-body inhalation. Mortality, clinical signs, body weight, hematology, serum chemistry, estrous cycle parameters, performance in the Morris water maze test, and organ weights, as well as gross and histopathological findings, were compared between the control and BPA exposure groups. Statistically significant changes were observed in serum chemistry and organ weights upon exposure to BPA. However, there was no BPA-related toxic effect on the body weight, food consumption, hematology, serum chemistry, organ weights, estrous cycle, performance in the Morris water maze test, or gross or histopathological lesions in any male or female rats in the BPA exposure groups. In conclusion, the results of this study suggested that the no observable adverse effect level (NOAEL) for BPA in rats is above $90mg/m^3$/6 hr/day, 5 days/week upon 8-week exposure. Furthermore, BPA did not affect the estrous cycle, spatial learning, or memory in rats.

• Journal of electromagnetic engineering and science
• /
• v.15 no.3
• /
• pp.151-157
• /
• 2015

The increasing use of mobile phones has raised public concern about the possible biological effects of radiofrequency electromagnetic field (RF-EMF) exposure on the human brain. To investigate the potential effect of RF-EMF exposure on the brain, we examined the behaviors and hippocampal morphology of C57BL/6 mice after sub-chronic exposure to RF-EMFs with a relatively high SAR level (5.0 W/kg). We applied a 2-hour daily exposure of WCDMA 1,950 MHz using a reverberation chamber that was designed for whole-body exposure for 60 days. In the behavioral tests, RF-EMF did not alter the physical activity or long-term memory of mice. Moreover, no alteration was found in the neuronal and glial cells in the hippocampus by RF-EMFs. In this study, we showed that sub-chronic whole body RF exposure did not produce memory impairment and hippocampal morphological alteration in C57BL/6 mice.

• Journal of Radiation Protection and Research
• /
• v.34 no.3
• /
• pp.121-128
• /
• 2009

During the maintenance period at Korean nuclear power plants, internal exposure of radiation workers occurred by the inhalation of $^{131}I$ released to the reactor building when primary system was opened. The internal radioactivity of radiation workers contaminated by $^{131}I$ was immediately measured using a whole body counter and the whole body counting was performed again after a few days. In this study, the intake estimated from the record history of entrance to radiation control areas and the measurement results of air sampling for $^{131}I$ in those areas, were compared with that from the results of whole body counting. As a result, it was concluded that the intake estimation using whole body counting and air sampling showed similar results.

• Journal of radiological science and technology
• /
• v.41 no.5
• /
• pp.437-444
• /
• 2018

Whole-Body counters have been used to evaluate the internal contamination of gamma emitting radionuclides. Among the whole-body counters used in domestic nuclear facilities, Fastscan made by CANBERRA contains 2 NaI(Tl) detectors and is generally used to monitor the primary internal exposure. It has the advantage of achieving MDA even with short time measurements. Accuscan is a bed type, and has good energy resolution because it is composed of HPGe detector. Since the Accuscan with better energy resolution than Fastscan has better able to identify radionuclides, it is used to monitor secondary internal exposure. Some nuclear facilities have only Fastscan. We analyzed statistically whether Fastscan is enough to ensure accuracy and precision comparing with Accuscan. To do this, we prepared a CRM created by the Korea Research Institute of Standards and Science. We also obtained the data of 6 Fastscans and 5 Accuscans in domestic nuclear facilities. As a result of the study, although Fastscan compared with Accuscan is not as accurate as the Accuscan, the precision is statistically same. However, accuracy of Fastscan is in compliance with international standards except low energy range. In terms of accuracy and precision except radionuclides emitting low energy, it is possible to measure radioactivity inside workers even in nuclear facilities where only Fastscan is used.