• Journal of the Korean Society of Safety
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• v.8 no.1
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• pp.6-12
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• 1993

Now it is reported that there are many companies and factories which confront to the problem of false alarm in Automatic Fire Detecting System (AFDS). Though an AFDS is a high-priced and very important device in detecting a fire. the problem degrades the reliability and utility, eventually faith. of the system. This is a research concerned about the problem of false alarm of fire detectors in an AFDS. Structure of detectors was modeled up as a general K out-of n system. and reliability characteristics including false alarm rate and missed alarm rate, are derived from it. For decision of an optimal structure of detectors. preliminary analysis on various criteria is accomplished. It is concluded that appropriate modification of a detector with plural sensors may increase the system reliability and decrease the false alarm rate.

• Journal of the Korean Society of Safety
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• v.8 no.1
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• pp.54-58
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• 1993

The fatigue growth behavior of short cracks were studied various load ratios. Computer-aided unloading elastic compliance method was employed to measure the closure and the length of short cracks. In the dc/dN-$\Delta$K relationships. the decreasing behavior of the growth rate of short cracks is due to the decrease of crack opening ratio with increasing crack length. Irrespective of load ratio. the growth rate of short cracks can be well decribed in terms of the effective stress intensity factor range $\Delta$K$_{eff}$, which is calculated on the base of crack closure. dc/dN-$\Delta$K$_{eff}$ relationships of short cracks are found to coincide well with the corresponding long crack relationships. accordingly. the growth rate of short cracks can be predicted using that of long cracks.ort cracks can be predicted using that of long cracks.cks.

• Journal of the Korean Society of Safety
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• v.15 no.3
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• pp.83-87
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• 2000

Combustion characteristics of immobilized benzene and toluene in sands were studied. Experiments were performed by burning benzene and toluene immobilized on sands(particle size 0.1~0.5mm) to measure combustion rate and combustion temperature. The longer time from ignition to extinguishment was resulted from the larger particle size exhibited the higher mass burning rate. Of aromatic compounds tested the relative magnitude of facilitation of combustion was benzene and toluene. Combustion temperature of benzene and toluene without regard to the types of benzene and toluene was not increased with smaller sand. However, with larger sands, combustion temperature of benzene and toluene were increased by 50~$100^{\circ}C$ and the highest combustion temperature was obtained with larger sands.

• Nuclear Engineering and Technology
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• v.53 no.4
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• pp.1250-1258
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• 2021

In this paper, the mechanical performance of cracked surface-coated Zircaloy cladding, which has different coating materials, coating thicknesses and initial crack lengths, has been investigated. By analyzing the stress field near the crack tip, the safety zone range of initial crack length has been decided. In order to determine whether the crack can propagate along the radial (r) or axial (z) directions, the energy release rate has been calculated. By comparing the energy release rate with fracture toughness of materials, we can divide the initial crack lengths into three zones: safety zone, discussion zone and danger zone. The results show that Cr is suitable coating material for the cladding with a thin coating while Fe-Cr-Al have a better fracture mechanical performance in the cladding with thick coating. The Si-coated and SiC-coated claddings are suitable for reactors with low power fuel elements. Conclusions in this paper can provide reference and guidance for the cladding design of nuclear fuel elements.

• Journal of Auto-vehicle Safety Association
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• v.14 no.4
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• pp.16-20
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• 2022

Accurate state estimation is important for autonomous driving. However, the estimation error increases in situations that a lot of longitudinal slip occurs. Therefore, this paper presents a vehicle state estimation method using an Extended Kalman Filter. The filter estimates the states of the host vehicle robust to wheel slip. It utilizes the measurements of the four-wheel rotational speeds, longitudinal acceleration, yaw-rate, and steering wheel angle. Nonlinear measurement model is represented by Ackermann Model. The main advantage of this approach is the accurate estimation of yaw rate due to the measurement of the steering wheel angle. The proposed algorithm is verified in scenarios of autonomous emergency braking (AEB), lane change (LC), lane keeping (LK) using an automated vehicle. The results show that the proposed algorithm guarantees accurate estimation in such scenarios.

• International conference on construction engineering and project management
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• 2017.10a
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• pp.124-132
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• 2017

This paper describes the Around View Monitoring (AVM) system for hydraulic excavators that prevents the safety accidents caused by blind spots and increases the operational efficiency. To verify the developed system, experiments were conducted with its prototype. The experimental results demonstrate its applicability in the field with the following values: 7m of a visual range, 15fps of image refresh rate, 300ms of working information data reception rate, and 300ms of surface condition data reception rate.

• Journal of the Korean Society of Safety
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• v.22 no.4
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• pp.96-101
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• 2007

Usually pictograms embedded in safety signs are such final means to transmit hazard information that the importance of them cannot be emphasized too much. Nevertheless, in Korea, few people are interested in safety signs and their functions so that evaluation of safety signs are seldom committed nor safety signs draw workers' attention to fulfill their functions. Therefore this research aimed to standardize the procedure for developing safety signs in order not only to give practical help to industrial workers but to match them international standards, and to develop a few examples through the suggested standard procedure. As results, a procedure for developing industrial safety signs was developed by combining both ANSI Z535.3 and ISO 9186 with a special emphasis on action inducibility as the former emphasized as well as comprehensibility as the latter suggested. According to test results with undergraduate students as well as industrial workers on a few signs developed through the suggested procedure, action inducibility was higher whereas confusion rate was lower than expected on one hand, and it could be concluded that the procedure would supply results that can be satisfied on the other hand.

• Journal of dental hygiene science
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• v.18 no.5
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• pp.288-295
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• 2018

The purpose of this study was to investigate the attitudes and performing confidence, and factors influencing patient safety of dental hygiene students. The questionnaire contained items on the subjects' general characteristics, attitudes, and performing confidence in relation to patient safety. The self-reported questionnaire was administered to 287 dental hygiene students in Gwangju and Jeonnam, Korea from September to November 2017. We performed an independent t-test, one-way ANOVA analysis, Pearson's correlation coefficient, and multiple regression analysis using IBM SPSS ver. 21.0 software. As a result of differences in attitude, and performing confidence according to the general characteristics, attitude toward patient safety scored 3.48 out of 5 points, and was more positive in students from 4-year colleges, with high major satisfaction, and in students who answered that they needed patient safety education. Performing confidence for patient safety scored 3.57 out of 5 points, and was statistically significantly higher in 4-year college students, with higher major satisfaction, amongst those with experience in patient safety education, and when patient safety education was needed before clinical practice or employment. There were positive correlations between attitude and performing confidence for patient safety. As a result of analyzing the factors influencing attitude and performing confidence for patient safety, attitudes were higher with higher performing confidence and performing confidence had the highest satisfaction rate of the major and patient safety education experience. Therefore, it is necessary to provide systematic education at universities reflecting the characteristics of dental medical institutions, as well as developing various education contents and education methods.

• Quality Improvement in Health Care
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• v.24 no.1
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• pp.23-29
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• 2018

Background: The purpose of this study was to examine undergraduate medical students' perceptions and intentions regarding patient safety during clinical clerkships. Methods: Cross-sectional and self-administered questionnaire survey was conducted on 34 students from one medical school using a modified version of the Medical Student Safety Attitudes and Professionalism Survey (MSSAPS). We assessed $4^{rd}-year$ medical students' perceptions of the cultures ('safety', 'teamwork', and 'error disclosure'), 'behavioural intentions' concerning patient safety issues and 'overall patient safety'. The overall response rate was 66.4%. Results: Among safety domains, "teamwork culture" was rated highest. "Error disclosure culture" received the lowest ratings. Regarding the error disclosure domain, only 10% of respondents reported that they have received education or training on how to disclose medical error to patients. Independent of survey domains, when students were asked "Overall, do you think your hospital is safe based on your clinical rotation?", 61.8% reported that the hospital was safe. Conclusions: Assessing students' perceptions of safety culture can provide clerkship directors and educators with information that enhances the educational environment and promotes patient safety. Discussions of medical errors, patient safety, and how best to incorporate an analysis of these issues into the existing curriculum are needed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.5
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• pp.3484-3490
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• 2015

Construction industry has a relatively higher accident rate compared to other industries, especially the serious accident rate including death. Ministry of Employment and Labor has not only implemented safety consciousness but also initiated the basic occupational safety and health training for the construction industry. Despite the effort, only a few sites follow the obligatory task and there are reports stating the effect of the education is minimal. As a result, this research aims to determine and analyze the current state of the basic occupational safety and health training including its lesson plan and method. Furthermore, by analyzing the preliminary study on the effective instructional method, this research suggests an effective method to implement safety consciousness to the workers. An improvement plan is also suggested by supplying appropriate educational material to different workers by differentiating the characteristics and the cause of death at various work types in construction sites.