• Proceedings of the Safety Management and Science Conference
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• 2003.11a
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• pp.335-343
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• 2003

In the electrode fabrication of unit cell, it was ascertained that electrochemical characteristics were greatly increased with 90 wt.% of BP-20, 5 wt.% of Super P and 5 wt.% of mixed binder [P(VdF-co-HFP) : PVP =7 : 3] The self-discharge of unit cell showed that diffusion process was controlled by the ion concentration difference of initial electrolyte due to the characteristics of Electric Double Layer Capacitor (EDLC) charged by ion adsorption in the beginning, but this by current leakage through the double-layer at the electrode/electrolyte interface had a minor effect and voltages of curves were remained constant regardless of electrode material. The electrochemical characteristics of 2.3 V/3,000 F grade EDLC were as follows: 0.35 m of DC-ESR (100 A discharge), 0.14 mof AC-ESR (AC amplitude 100 mV), 2.80 Wh/kg (3.73 Wh/L) of energy density and 4.64 kW /kg (6.19 kW/L) of power density. Power output was compatible with electric vehicle applications, uninterrupted power supply and engine starter, in due consideration of Ragone relations.

• Journal of the Korea Safety Management & Science
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• v.14 no.3
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• pp.85-92
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• 2012

In this study the real situation of apartment house in seoul is reproduced with multi-zone modeling program contam2.4. This model include immune building system(disinfection system) which is consist of dilution, Filter Technology and UVGI(ultra violet germicidal irrdiation). In this study experiments design method used for estimating interaction of HRV air change rate, UVGI air change rate and UVGI grade. Result show that HRV air change rate and UVGI air change rate is most influence factor for remove rate. also Interaction of HRV air change rate and UVGI air change rate is ost influence factor for remove rate.

• Safety and Health at Work
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• v.2 no.4
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• pp.336-347
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• 2011

Objectives: In Korea, an average of 258 workers claim compensation for their noise-induced hearing loss (NIHL) on an annual basis. Indeed, hearing disorder ranks first in the number of diagnoses made by occupational medical check-ups. Against this backdrop, this study analyzed the impact of 19 types of noise-generating machines and equipment on the sound pressure levels in workplaces and NIHL occurrence based on a 2009 national survey on work environments. Methods: Through this analysis, a series of statistical models were built to determine posterior probabilities for each worksite with an aim to present risk ratings for noise levels at work. Results: It was found that air compressors and grinding machines came in first and second, respectively in the number of installed noise-generating machines and equipment. However, there was no direct relationship between workplace noise and NIHL among workers since noise-control equipment and protective gear had been in place. By building a logistic regression model and neural network, statistical models were set to identify the influence of the noise-generating machines and equipment on workplace noise levels and NIHL occurrence. Conclusion: This study offered NIHL prevention measures which are fit for the worksites in each risk grade.

• Journal of the Korea Safety Management & Science
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• v.10 no.3
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• pp.29-33
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• 2008

According to statistics released by the Ministry of Labor for the past 6 years, work-related accidents in the construction industry have been on the continued increase, resulting in social and economic losses that are difficult to determine at an exact amount. However, the number will likely get much bigger if unreported cases are included, considering the fact that the aforementioned statistics are based soley on the applications filed with Korea Workers' Compensation and Welfare Service. The practice of businesses choosing not to report and dealing with industrial accidents in an unauthorized manner is defined as "concealment of industrial accident". The reason the employers tend to engage in the concealment practice even at their huge cost is a "pre-qualification" scheme for the applicants in the government procurement process. Under the pre-qualification scheme, the applicants with a high rate of industrial accidents receive a low grade and become less attractive candidates in the procurement process, thus losing an opportunity to win a contract. Such failure relates directly to the fate of business organizations, to survive or not. That is why they are making all-out efforts to obtain a high grade in the pre-qualification evaluation. With regard to the accident-concealment problem, the following can be mentioned as preventive measures: (1) To exclude a rate of industrial accidents from the pre-qualification scheme; (2) To strengthen the institution of imposing penalties on the occurrence of industrial accidents; (3) To introduce private insurance system to the current industrial accident compensation insurance; and (4) To give non-recognition treatment to industrial accidents that were not reported upon occurrence. In conclusion, the concealment problem can be resolved if the aforementioned measures are to be taken continuously along with corrective measures against institutional deficiencies.

• Journal of the Korean Society for Railway
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• v.14 no.4
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• pp.333-340
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• 2011

The purpose of this paper is to develop two kinds of finite element models for the heavy deformable obstacle defined in grade crossing collision scenario of the Europe TSI and the Korean rolling stock safety regulations and to apply the crashworthiness evaluation for the Korean high-speed EMU with the FE model. The numerical models of the heavy obstacle were changed from a past rigid one to a current deformable one whose stiffness requirement should be verified by a collision simulation defined in the regulations. Through several trial simulations, two types of numerical models for the heavy obstacle were developed, which satisfied physical properties specifies in the regulations. One is a solid-type obstacle with uniform density and the other is a shell-type. With the obstacles developed in this study, the grade crossing collision scenario for Korean high-speed EMU was simulated and evaluated for the two-type obstacle models. From the simulation results, the shell and solid-type obstacles showed quite different behaviors after collision, and the shell type model gave more severe results.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.31 no.4
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• pp.295-303
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• 2021

Objective: Paint manufacturing industry workers are exposed to various lung cancer carcinogenic substances including hexavalent chromium and crystalline silica. Studies have been conducted on lung cancer in Paint manufacturing industry workers and the concentration of hexavalent chromium in paint industry; however, the concentration of crystalline silica and hexavalent chromium and cases of lung cancer in a single Paint factory has never been reported in Korea. Methods: To determine whether the cancer was related to his work environment, we assessed the level of exposure to carcinogens during pouring and mixing talc and pigment. In addition, a mask fit test was performed for the worker. Results: Analysis of talc and silica bulk powder materials showed that crystalline silica (quartz) was 5% in talc and 100% in silica. The green and yellow pigments contained 87% and 92% of lead chromate, respectively. Our quantitative analysis of pigment powder samples showed that the hexavalent chromium contents quantified in the green and yellow pigment samples were 87% and 92%, respectively. In order to estimate his exposure level of hexavalent chromium, we measured a personal exposure level of hexavalent chromium for a worker in accordance with the National Institute for Occupational Safety and Health #7605 method. The results showed that the worker was exposed to the high level of hexavalent chromium (0.033 mg m-3). In addition, the talc powder also contained 5% quartz, and the worker's exposure level to respirable quartz exceeded OEL. As a result of the respiratory protection fit test for workers, the overall Fit Factor was '15' when wearing a second-grade mask and '25' when wearing a first-grade mask, significantly lower than the US Occupational Safety and Health Agency (OSHA) pass value of "100". Conclusion: Workers who pouring and mixing powder materials such as talc or colored pigments in paint manufacturing company may be exposed to high concentrations of carcinogenic substances. These findings indicate that it is necessary to local ventilation system inspection, safety and health education for employers and workers, and periodically monitoring and manage the working environment.

• Journal of the Korean Institute of Gas
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• v.26 no.3
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• pp.38-44
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• 2022

As the supply of hydrogen charging stations for hydrogen supply accelerates due to the hydrogen economy revitalization policy, the risk of accidents is also increasing. Since most hydrogen explosion accidents lead to major accidents, it is very important to secure safety when using hydrogen energy. In order to utilize hydrogen energy, it is essential to secure the safety of hydrogen storage containers used for production, storage, and transportation of liquid hydrogen. In this paper, in order to evaluate the structural safety of a hydrogen-filled pressure vessel, the behavioral characteristics of gas pressure were analyzed by finite element analysis. SA-372 Grade J / Class 70 was used for the material of the pressure vessel, and a hexahedral mesh was applied in the analysis model considering only the 1/4 shape because the pressure vessel is axisymmetric. A finite element analysis was performed at the maximum pressure using a hydrogen gas pressure vessel, and the von Mises stress, deformation, and strain energy density of the vessel were observed.

• Journal of the Korean Society of Safety
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• v.39 no.2
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• pp.1-8
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• 2024

Unwanted effects of electrostatic phenomena occur in various industries. Electrostatic problems originating from the human body in flammable atmospheres in the industry are especially concerning. A substantial volume of experimental data on the electrostatic charging voltages created on the human body owing to the rubbing of apparel were generated and reviewed during this study. The data were reviewed to determine whether the resultant charging levels of the human body are hazardous in flammable atmospheres. This study was conducted under several conditions, such as different fiber types used in apparel, shoe types, and relative humidities (RHs). The following conclusions were drawn in this study. ① The electrostatic charging levels of the human body owing to the rubbing of apparel increase with the increase in the surface resistances of apparel; however, the electrostatic charging levels may be different depending on the condition of the cloth surface. ② The discharging energy of 1.98-18.5 [mJ] from the human body exceeds the minimum ignition energy of most flammable materials, when removing an overcoat made of polyester, cotton and wool under severe conditions such as wearing height-raising shoes for men. ③ When removing antistatic apparel, the maximum discharging energy of 0.128 mJ from the human body is dangerous if the minimum ignition energy of the flammable material is between 10^-5-10^-4 [J] Grade; however, a minimum ignition energy of 10^-3 J Grade of the flammable material is considered safe. ④ While wearing antistatic shoes, the electrostatic charging voltage generated in the human body when removing an overcoat is 30 V; therefore, wearing such shoes is a suitable countermeasure when handling flammable materials. However, the antistatic abilities of shoes reduce when thick socks are worn. ⑤ As RH increases, the electrostatic charging levels of the human body decrease. ⑥ The electrostatic charging levels of the human body from removing a cotton overcoat can ignite the majority of flammable materials when RH is less than 30% under severe conditions such as wearing height-raising shoes for men.

• Journal of The Korean Society of Integrative Medicine
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• v.6 no.3
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• pp.73-81
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• 2018

Purpose : This study identified knowledge, attitudes and behavior for radiation safety management of dental hygiene student. And to provide basic data for the development of effective education program for safety management for radiation protection. Methods : A questionnaire survey of questionnaires was conducted on the second and third grade dental hygiene students at three - year college in 'A' area of Gyeongnam province. The questionnaire of 37 items was used to investigate knowledge and attitude about radiation protection. The collected data were analyzed using frequency analysis, mean, standard deviation, t-test, ANOVA and pearson's correlation Analysis using the SPSS 21.0 program. Result : Results obtained from this study are as follows. 1. Knowledge level of radiation safety management by general characteristics showed statistically significant difference. 2. Radiation safety education knowledge score was higher in the case of radiation safety education(t=1.660, p<.05). 3. The radiation safety management attitude score was a statistically significant difference between the groups according to 'achievement' (F=1.660, p<.001). In the case of 'radiation protection facilities', there was a statistically significant difference between groups according to the recognition of radiation protection facilities (F=6.001, p<.001). 4. As a result of investigating the relationship between radiation safety management knowledge and attitude, the higher the knowledge level of radiation safety management, the higher the attitude(p<.001). Conclusion : Therefore, radiation safety management education should be organized systematically and it is required to improve not only safety management knowledge, attitude level but also action level.

• The Journal of the Convergence on Culture Technology
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• v.8 no.1
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• pp.131-138
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• 2022

This study was to investigate the characteristics of nursing students' safety by reviewing literature reported in Korea. Methods: A total of 29 articles were selected by the combination with 'safety', 'safety*', 'patient safety', 'patient safety*' 'nursing students', and 'nursing * students' from the database(via DBpia, KCI, KISS, NANET, NDSL, NL, RISS). Results: Publication year of researchs are '2015-2019' 69.0%, publication journal 'non-nursing' 79.3%, mean of participants 242.4 persons, 'under 200 persons' 51.7%, number of participating area 'one region' 48.2%, number of participating schools 'over three schools' 42.3%, participating grade 'senior in colleges' 56.2%. Participant were calculated by G*Power and unapproved by Institutional Review of Board(IRB) were 58.6%. Most of statistics measures were 'regression' 75.9%, and authors' number were '2 co-authors' 58.6%. In keyword analysis, it has changed from knowledge-oriented to patient-centered. Conclusion: Future research will require research and policy support for the development of an integrated educational approach and intervention plan to strengthen the safety competency of nursing students.