• Food Science and Biotechnology
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• v.18 no.4
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• pp.895-899
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• 2009

A new approach for the determination of acrylamide (AM) in foods by solid phase microextraction-gas chromatography (SPME-GC) was established. AM was bromized and transformed to 2-bromoacrylamide (2-BAM). 2-BAM was then extracted by a commercial SPME fiber, $75-{\mu}m$ Car/PDMS fiber, for GC detection. The influence of extraction and desorption parameters such as extraction temperature and time, stirring rate, desorption temperature, and time were studied and optimized. The mass concentration was proportional to the peak area of 2-BPA from 1.0 to 8,000 ${\mu}g/L$. The detection limit of the SPME-GC for 2-BAM was found to be 0.1 ${\mu}g/L$, and the recoveries and relative standard deviations for different food samples were 74.5 to 102.0%, and 4.2 to 9.1%, respectively. The presented method was applied to the determination of AM in fried foods.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.344-352
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• 2022

Accurate indoor localization of construction workers and mobile assets is essential in safety management. Existing positioning methods based on GPS, wireless, vision, or sensor based RTLS are erroneous or expensive in large-scale indoor environments. Tightly coupled sensor fusion mitigates these limitations. This research paper proposes a state-of-the-art positioning methodology, addressing the existing limitations, by integrating Stereo Visual Inertial Odometry (SVIO) with fiducial landmarks called AprilTags. SVIO determines the relative position of the moving assets or workers from the initial starting point. This relative position is transformed to an absolute position when AprilTag placed at various entry points is decoded. The proposed solution is tested on the NVIDIA ISAAC SIM virtual environment, where the trajectory of the indoor moving forklift is estimated. The results show accurate localization of the moving asset within any indoor or underground environment. The system can be utilized in various use cases to increase productivity and improve safety at construction sites, contributing towards 1) indoor monitoring of man machinery coactivity for collision avoidance and 2) precise real-time knowledge of who is doing what and where.

• Wind and Structures
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• v.27 no.4
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• pp.255-267
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• 2018

This paper investigated the wind-snow flow around the bogie region of a high-speed train under crosswinds using a coupled numerical method of the unsteady Realizable $k-{\varepsilon}$ turbulence model and discrete phase model (DPM). The flow features around the bogie region were discussed and the influence of bogie fairing height on the snow accumulation on the bogie was also analyzed. Here the high-speed train was running at a speed of 200 km/h in a natural environment with the crosswind speed of 15 m/s. The mesh resolution and methodology for CFD analysis were validated against wind tunnel experiments. The results show that large negative pressure occurs locally on the bottom of wheels, electric motors, gear covers, while the positive pressure occurs locally on those windward surfaces. The airflow travels through the complex bogie and flows towards the rear bogie plate, causing a backflow in the upper space of the bogie region. The snow particles mainly accumulate on the wheels, electric motors, windward sides of gear covers, side fairings and back plate of the bogie. Longer side fairings increase the snow accumulation on the bogie, especially on the back plate, side fairings and brake clamps. However, the fairing height shows little impact on snow accumulation on the upper region of the bogie. Compared to short side fairings, a full length side fairing model contributes to more than two times of snow accumulation on the brake clamps, and more than 20% on the whole bogie.

• Nuclear Engineering and Technology
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• v.52 no.7
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• pp.1557-1564
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• 2020

In this paper, 3D model-based interactive gamma ray shielding package (MIGSHIELD) is developed in virtual reality platform for windows operating system. In MIGSHIELD, the computational methodology is based on point kernel algorithm (PK), several key parameters of PK are obtained using new technique and new methods. MIGSHIELD has interactive capability with virtual world. The main features made in the MIGSHIELD are (i) handling of physical information from virtual world, (ii) handling of arbitrary shapes radioactive source, (iii) calculating the mean free path of gamma ray, (iv) providing interactive function between PK and virtual world, (v) making better use of PK for virtual simulation, (vi) plug and play. The developed package will be of immense use for calculations involving radiation dose assessment in nuclear safety and contributing to fast radiation simulation for virtual nuclear facilities.

• Journal of Technologic Dentistry
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• v.39 no.3
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• pp.179-185
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• 2017

Purpose: It is intended to raise awareness of importance of protective equipment and necessity of safety education by examining the actual condition of measures to deal with accident, occurrence of injury, whether safety education is received or not, the actual condition of wearing protective equipment, and working environment of dental lab and dental technician. Methods: A self-administered survey was conducted for a total of 150 dental technologists. A chi-squared test and independent-samples t-test was carried out by using SPSS WIN Program (version 12.0) in order to analyze the actual condition of safety education according to work experience and position and whether injury occurred according to whether to wear protective equipment. Significance level was 0.05. Results: With regard to whether injury occurred according to whether safety education was received, there was 'receiving the safety education-injured (71.8%)', 'not receiving the safety education-injured (79.7%)', 'receiving the safety education-not injured (28.2%)', and 'not receiving the safety education-not injured (20.3%)'. The statistical results of injury occurrence according to safety education were not significant. With regard to whether to be injured according work experience, there was 'less than 10 years-injured (68.4%)', 'less than 10 years- not injured (31.6%)', '10 years or above-injured (89.1%)', and '10 years or above-not injured (10.9%)'. The statistical results of injury occurrence according to work experience were significant (p<0.001). Conclusion: Dental lab and specialized agencies should continue to be interested in periodic safety training, recommending wearing protective equipment and personal protective equipment support and so on.

• Bulletin of the Korean Space Science Society
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• 2004.10b
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• pp.106-106
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• 2004

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.17 no.3
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• pp.192-202
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• 2007

Objectives: The objectives of this research are to examine the missions, organization, and programs of the environmental, health and safety(EHS) offices of the major research universities in the U.S.A., particularly the case of Massachusetts Institute of Technology(MIT) EHS Office, and to suggest ways to address the EHS issues of the universities and research institutes in South Korea. Methods: The top 30 research universities in the U.S.A. were selected by the total amounts of research funds they annually received. The web sites of the 30 universities were searched to identify the names of the departments that address environment, health, and/or safety related issues, the missions of those departments, the major programs of those departments, and the number of staff in those departments. Also, a case study was conducted for the Environment Health and Safety Management System and the Environment, Health and Safety Office of the MIT, using literature and web searches and a meeting with the Director of the MIT Environment, Health and Safety Office. Results: All the top 30 research universities in the U.S.A. had designated departments that dealt with EHS issues. Most of them were by the name of or similar to environmental, health and safety. The mission statements of those departments were mostly about improving the safety and health of their community members, improving the environment, and complying to EHS regulations. Most of those departments had an environmental management program, industrial hygiene program, radiation protection program, safety program, and biosafety program as their major programs. The components of the environment, health and safety management system(EHS-MS) of the MIT were examined in detail. In contrast, not many universities in South Korea had designated departments that dealt specifically with EHS issues. Also, the number of fulltime staff for EHS was only 1-2 in most of the Korean universities and their work duties included only general safety, while neglecting other health/environment related issues. Conclusions: Well organized and functioning environmental, health and safety offices were present in all of the top 30 research universities in the U.S.A., whereas similar organizations of the universities in South Korea were virtually non-existent and/or had very limited EHS activities. Therefore, in order to reduce potential risks of accidents and health problems in the Korean universities and research institutions, well established and functioning EHS-MSs and EHS offices are warranted. The case of the EHS-MS and EHS Office in the MIT demonstrate a successful case to follow.

• Nuclear Engineering and Technology
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• v.51 no.4
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• pp.987-995
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• 2019

Steam jet condensation is of great importance to pressure suppression containment and automatic depressurization system in nuclear power plant. In this paper, the condensation processes of sonic steam jet in a quiescent subcooled pool are recorded and analyzed, more precise understanding are got in direct contact condensation. Experiments are conducted at atmospheric pressure, and the steam is injected into the subcooled water pool through a vertical nozzle with the inner diameter of 10 mm, water temperature in the range of $25-60^{\circ}C$ and mass velocity in the range of $320-1080kg/m^2s$. Richardson number is calculated based on the conservation of momentum for single water jet and its values are in the range of 0.16-2.67. There is no thermal stratification observed in the water pool. Four condensation regimes are observed, including condensation oscillation, contraction, expansion-contraction and double expansion-contraction shapes. A condensation regime map is present based on steam mass velocity and water temperature. The dimensionless steam plume length increase with the increase of steam mass velocity and water temperature, and its values are in the range of 1.4-9.0. Condensation heat transfer coefficient decreases with the increase of steam mass velocity and water temperature, and its values are in the range of $1.44-3.65MW/m^2^{\circ}C$. New more accurate semi-empirical correlations for prediction of the dimensionless steam plume length and condensation heat transfer coefficient are proposed respectively. The discrepancy of predicted plume length is within ${\pm}10%$ for present experimental results and ${\pm}25%$ for previous researchers. The discrepancy of predicted condensation heat transfer coefficient is with ${\pm}12%$.

• Safety and Health at Work
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• v.7 no.4
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• pp.381-388
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• 2016

Background: Relationships among portable scanning mobility particle sizer (P-SMPS), condensation particle counter (CPC), and surface area monitor (SAM), which are different metric measurement devices, were investigated, and two widely used research grade (RG)-SMPSs were compared to harmonize the measurement protocols. Methods: Pearson correlation analysis was performed to compare the relation between P-SMPS, CPC, and SAM and two common RG-SMPS. Results: For laboratory and engineered nanoparticle (ENP) workplaces, correlation among devices showed good relationships. Correlation among devices was fair in unintended nanoparticle (UNP)-emitting workplaces. This is partly explained by the fact that shape of particles was not spherical, although calibration of sampling instruments was performed using spherical particles and the concentration was very high at the UNP workplaces to allow them to aggregate more easily. Chain-like particles were found by scanning electron microscope in UNP workplaces. The CPC or SAM could be used as an alternative instrument instead of SMPS at the ENP-handling workplaces. At the UNP workplaces, where concentration is high, real-time instruments should be used with caution. There are significant differences between the two SMPSs tested. TSI SMPS showed about 20% higher concentration than the Grimm SMPS in all workplaces. Conclusions: For nanoparticle measurement, CPC and SAM might be useful to find source of emission at laboratory and ENP workplaces instead of P-SMPS in the first stage. An SMPS is required to measure with high accuracy. Caution is necessary when comparing data from different nanoparticle measurement devices and RG-SMPSs.

• Journal of the Korean Society of Safety
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• v.33 no.5
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• pp.170-176
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• 2018

Laboratory inspection and diagnosis is a means of investigating and assessing various hazards or the state of research equipment in a laboratory, then taking appropriate safety measures to prevent accidents and injury. In many cases, laboratory inspection and diagnosis carried out by agencies are performed in a perfunctory manner that only barely satisfies the legal requirements. The aim of the present study is to provide clearly established pricing criteria for laboratory inspection and diagnosis, so as to prevent recurrence of laboratory accidents and to establish a safe laboratory environment. In order to clarify previously unclear matters, such as the lower limit for bids submitted by laboratory inspection and diagnosis agencies, technical manpower requirements, and number of laboratories inspected and diagnosed per day, a questionnaire survey was administered to agency personnel. First, when asked what the lower limit for bids submitted by agencies should be in order to improve reliability of inspection and diagnosis results and make up for the shortcomings of the lowest-bidder-wins system, 85.5% of respondents answered that the lower limit for bids should stand at no lower than 90% of the estimated price. The level of technical expertise among the technical personnel committed to laboratory inspection and diagnosis was shown to impact the reliability of results, and questionnaire results indicated a need to vary technical expertise levels depending on the degree of hazard, substances handled, and equipment used in a given laboratory. Level of technical expertise(67.1%) and number of personnel(52.6%) were shown to have a greater impact on reliability of diagnosis than on reliability of inspection. According to the results, it is determined that three persons(specialist, advanced and intermediate) should be committed to inspections, while four persons(professional, specialist, advanced and intermediate) should be committed to diagnoses. The respondents indicated a larger number of laboratories could be inspected than diagnosed per day. This can be attributed to differences in the amount of work each task involves, and the time each task takes. Assuming a six-hour work day not counting transportation, paperwork and rest, it is thought that inspection of up to 36 laboratories will be possible if each laboratory is assigned no more than 10 minutes(34.7%), while up to 24 laboratories could be inspected and diagnosed if each laboratory is assigned 15 to 20 minutes(35.1%).