• Structural Engineering and Mechanics
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• v.80 no.6
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• pp.749-765
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• 2021

Suspension bridges bear large eccentric live loads in rush hours when most vehicles travel in one direction on the left or right side of the bridge. With the increasing number and weight of vehicles and the girder widening, the eccentric live load effect on the bridge behavior, including bending and distortion of the main girder, gets more pronounced, even jeopardizing bridge safety. This study proposes an analytical algorithm based on multi-catenary theory for predicting the suspension bridge responses to eccentric live load via the nonlinear generalized reduced gradient method. A set of governing equations is derived to solve the following unknown values: the girder rigid-body displacement in the longitudinal direction; the horizontal projection lengths of main cable's segments; the parameters of catenary equations and horizontal forces of the side span cable segments and the leftmost segments of middle span cables; the suspender tensions and the bearing reactions. Then girder's responses, including rigid-body displacement in the longitudinal direction, deflections, and torsion angles; suspenders' responses, including the suspender tensions and the hanging point displacements; main cables' responses, including the horizontal forces of each segment; and the longitudinal displacement of the pylons' tower top under eccentric load can be calculated. The response of an exemplar suspension bridge with three spans of 168, 548, and 168 m is calculated by the proposed analytical method and the finite element method in two eccentric live load cases, and their results prove the former's feasibility. The nonuniform distribution of the live load in the lateral direction is shown to impose a greater threat to suspension bridge safety than that in the longitudinal direction, while some other specific features revealed by the proposed method are discussed in detail.

• Journal of the Korean Society of Safety
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• v.28 no.5
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• pp.1-4
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• 2013

The main objective was to design and develop a prototype robot system for assessing slip resistance. The developed robot system will be able to be used for stochastic nature of friction in the whole workplace. The second objective was to evaluate its operating condition in the laboratory, using a dreg sled type slipmeter(BOT-3000) as reference device. It was found that COF(Coefficient of Friction) measured with robot system was similar to that of BOT-3000 when sliding velocity was reached at 0.2m/s. The robot system might be the more promising one than any traditional measurement devices. A further evolution of prototype devices, as well as the development of test methods for that's various applications, is to be started in forthcoming studies.

• Journal of Environmental Health Sciences
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• v.36 no.5
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• pp.343-350
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• 2010

This study was performed to investigate laboratory workers' exposures to airborne nanoparticles at a university laboratory where acid treatment experiments were conducted on the surfaces of engineered carbon nanotubes (CNTs). The surface area concentrations, number concentrations, and mass concentrations of airborne nanoparticles were measured at personal breathing zones (PBZs) for various tasks using direct reading instruments. For all three metrics, airborne nanoparticle concentrations during the experiments were higher than background levels measured before and after the experiments for all three metrics. Among the various tasks that were performed as part of these experiments, one task that involved filtering a mixture of acid and CNTs showed the highest concentrations in all three metrics, with concentrations of $116.6\;{\mu}m^2$/cc, 24320 pt/cc, and $9.0\;{\mu}g/m^3$, respectively. Nanoparticle surface area concentrations measured at a representative area fluctuated with those at the PBZs in the laboratory. This result indicates that nanoparticles generated during the experiments were not just limited to the PBZs of the workers but were also present throughout the room, potentially exposing co-located workers. CNTs were detected by a transmission electron microscope in an air sample collected while handling the CNTs. All the tasks were performed inside fume hoods, with the sliding sashes open to their required heights. It was noted that the capture velocities of the fume hoods were much lower than the American National Standards Institute (ANSI)'s recommendation level (0.4 to 0.6 m/s). In conclusion, this study showed that, due to inadequate control, laboratory researchers performing acid treatment experiments on surfaces of CNTs were exposed to airborne nanoparticles generated during the tasks.

• Journal of the Korean Society of Safety
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• v.27 no.4
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• pp.96-100
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• 2012

Low back pain (LBP) is a major issue in modern industrialized society which is mainly caused by manual material handling (MMH) tasks. The objective of this study was to provide scientific data for establishing work standard for Korean workers throughout the laboratory experiment including some specific lifting tasks. Thirty male college students were recruited as participants. The maximum voluntary contraction (MVC), recommended weight limit (RWL), and psychophysical safety weight using Borg's CR-10 scale were studied. Results showed that the RWL was 8.4% MVC higher than the proposed psychophysical safety weight. Based on this result, it is suggested that the NIOSH lifting equation (NLE) should not be directly applied to Korean without reasonable modifications. The ratio of psychophysical safety weight to MVC was ranged from 20.1 to 26.4%. It is expected that use of the methodology in this study may provide better expectation of the work ability of Korean for reducing lower back pains caused by MMH.

• International Journal of Computer Science & Network Security
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• v.22 no.6
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• pp.109-114
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• 2022

The article is devoted to analyzing the police influence on road safety formation. The globalization processes confirm the study's relevance, provoking population mobility and the need to increase freight traffic. The study aims to identify the factors that affect road safety and the activities of the police and the EU transport safety units. An empirical analysis using factor analysis, correlation analysis, and general scientific methods of cognition were carried out to achieve the goal. The analysis results found that the number of police officers affects road safety, but not in all countries, which confirms the importance of other factors. Based on the analysis results of the scientific literature, the factors affecting transport safety are legislative regulation, the use of innovative technologies, transport infrastructure, geography, and psycho-physical and emotional drivers factors. It has been proved that the police authorities and units cannot fully ensure transport safety in the European Union because the safety is formed by a complex of actions by the state and road users.

• Animal Bioscience
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• v.37 no.7
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• pp.1213-1224
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• 2024

Objective: Enterotypes (ETs) are the clustering of gut microbial community structures, which could serve as indicators of growth performance and carcass traits. However, ETs have been sparsely investigated in waterfowl. The objective of this study was to identify the ileal ETs and explore the correlation of the ETs with growth performance and carcass traits in Muscovy ducks. Methods: A total of 200 Muscovy ducks were randomly selected from a population of 5,000 ducks at 70-day old, weighed and slaughtered. The growth performance and carcass traits, including body weight, dressed weight and evidenced weight, dressed percentage, percentage of apparent yield, breast muscle weight, leg muscle weight, percentage of leg muscle and percentage of breast muscle, were determined. The contents of ileum were collected for the isolation of DNA and 16S rRNA gene sequencing. The ETs were identified based on the 16S rRNA gene sequencing data and the correlation of the ETs with growth performance and carcass traits was performed by Spearman correlation analysis. Results: Three ETs (ET1, ET2, and ET3) were observed in the ileal microbiota of Muscovy ducks with significant differences in number of features and α-diversity among these ETs (p<0.05). Streptococcus, Candida Arthritis, and Bacteroidetes were the presentative genus in ET1 to ET3, respectively. Correlation analysis revealed that Lactococcus and Bradyrhizobium were significantly correlated with percentage of eviscerated yield and leg muscle weight (p<0.05) while ETs were found to have a close association with percentage of eviscerated yield, leg muscle weight, and percentage of leg muscle in Muscovy ducks. However, the growth performance of ducks with different ETs did not show significant difference (p>0.05). Lactococcus were found to be significantly correlated with leg muscle weight, dressed weight, and percentage of eviscerated yield. Conclusion: Our findings revealed a substantial variation in carcass traits associated with ETs in Muscovy ducks. It is implied that ETs might have the potential to serve as a valuable biomarker for assessing duck carcass traits. It would provide novel insights into the interaction of gut microbiota with growth performance and carcass traits of ducks.

• Journal of the Korea Safety Management & Science
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• v.9 no.3
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• pp.119-125
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• 2007

As competition in manufacturing enterprise is contested, the scope of safely production planning, manufacturing enterprise should ensure, has been reduced. The more upstream of SCM, the more reduction of scope of production planning. As a result, order fluctuation is more sharply contested. Through improving the logistics network, it is best way that the end user's demand information is conveyed to upstream of SCM, but it is difficult in fact. In this paper, it mention the way of robustic adjustment, in the suppliers' point of view, the end user's demand information is dammed up, as they postpone responding the customer's order as a possible. And it will show the result of appling the way, as a case study.

• Journal of The Korea Institute of Healthcare Architecture
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• v.22 no.3
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• pp.7-15
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• 2016

Purpose: As medicare services have gotten spreaded, clinical laboratory has been dominant position. So, it has been acted for quality control and clinical pathology accreditation. But there has been quite deficient information to evaluate working space and technical standards of medical laboratory for accreditation. This study goals to figure out accreditation standard and design guideline for clinical laboratory, and to give safe and efficient design information. Methods: This study has been searched by literature for accreditation standards and design guidelines of clinical pathology in USA, UK, and Germany. Results: Three countries have accredited based on working lab space, staff space, storage space, patient space and health and safety equipment. Design guidelines of three countries commonly have focused on worktable layout, worktable distance and module, and specific laboratory biosafety level. And USA guidelines stress on the architectural design such as design process and passage distance for escape, UK stress on the efficiency as functional work flow and construction cost, lastly Germany design guidelines stress on the operator's safety distance and workstation. Three countries have not only accreditation standards but also design guidelines for more specific quality management, separating from accrediting institute. Implications: In korea, it has been needed to make clinical laboratory design guideline for the safe and efficient environment and reliable and competitive medical service.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.10
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• pp.197-203
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• 2014

The safety and arming device(SAD), one of the components of the fuzes, shall provide safety that is consistent with handling, storage, transportation, use, and disposal. In this paper, we describes the design of the SAD which includes the solenoid assembly and the solenoid driving circuit to improve the safety of the fuzes. The solenoid assembly consists of a coil assembly, a restoring spring, and a core. The solenoid assembly is added in the SAD as an additional safety device. In case of the normal circumstances, the core of the solenoid assembly restrains the $1^{st}$ and $2^{nd}$ safety devices of the SAD for those devices not to operate at all, so that the SAD can secure safety for storage, transportation, and use. In contrast, when the battery power is provided to the solenoid driving circuit just before the flight, the core confirms the power level and starts removing the restraint from the $1^{st}$ and $2^{nd}$ safety devices of the SAD, and then the SAD is able to change its mode from safety mode to armed mode. After firing, once the SAD's operations complete, the turned-on arming switch stops providing the power to the solenoid assembly automatically. It can reduce the power consumption at solenoid assembly. Therefore, the proposed solenoid driving circuit for the solenoid assembly not only unlocks the restrained solenoid assembly from the safety devices, but also saves the power consumption during the flight.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.12
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• pp.942-952
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• 2018

A wireless power transfer (WPT) system for an urban railroad is currently under development in S. Korea. This system supplies power to railroad cars using 60 kHz magnetic fields. The electromagnetic fields (EMFs) generated by the WPT system should satisfy established safety requirements for exposure of the human body to these fields. However, EMF measurements and the safety assessment methods for fields generated by the WPT system have not yet been established. As such, a measurement and safety assessment method for EMF generated by a WPT system for an urban railroad is proposed in this report. The EMF generated by this WPT system on a test railroad was measured and compared to the reference level set by the human safety standard for EMF exposure.