• International Journal of Highway Engineering
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• v.15 no.4
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• pp.135-146
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• 2013

PURPOSES : This study aimed to analyze the impact the operation of pre-signals at 4-leg signalized intersections and present primary environmental factors of roads that need to be considered in the installation of pre-signals. METHODS : Shift of proportions safety effectiveness evaluation method which assesses shifts in proportions of target collision types to determine safety effectiveness was applied to analyze traffic crash by types. Also, Empirical Bayes before/after safety effectiveness evaluation method was adapted to analyze the impact pre-signal installation. Negative binomial regression was conducted to determine SPF(safety performance function). RESULTS : Pre-signals are effective in reducing the number of head on, right angle and sideswipe collisions and both the total number of personal injury crashes and severe crashes. Also, it is deemed that each factor used as an independent variable for the SPF model has strong correlation with the total number of personal injury crashes and severe crashes, and impacts general traffic crashes as a whole. CONCLUSIONS: This study suggests the following should be considered in pre-signal installation on intersections. 1) U-turns allowed in the front and rear 2) A high number of roads that connect to the intersection 3) Many right-turn traffic flows 4) Crosswalks installed in the front and rear 5) Insufficient left-turn lanes compared to left-turn traffic flows or no left-turn-only lane.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.55 no.12
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• pp.661-666
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• 2006

Interlocking signalling system plays key role as core system to manage railway operation. The core role of railway operation is to control routing, displaying signal and regulation for train. Interlocking system relate tightly to railway accident because collision and derailment is sometime taken place wrong route setting and signal displaying. Safety activity for interlocking system is inevitable to avoid the accident over its life cycle. The safety activity includes hazard identification and analysis, safety requirement allocation, safety plan, safety activity and ao on. The safety activity need a broad wide range work. In this paper, we concentrate on hazard identification for generic interlocking system and programmable electronic interlocking system and compare between two results. The hazards will be used for safety activity.

• Journal of radiological science and technology
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• v.46 no.2
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• pp.115-122
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• 2023

The purpose of this study was to examine the association between the shapes and colors of emergency exit symbols, magnetic field warning symbols, and radiation zone symbols used in hospitals for staff and patient safety and their effects on cognitive memory. The hippocampal region's signal intensity(SI) was analyzed using fMRI. The Symbol 2 (1.75±0.54) with a green background had the highest signal intensity (SI) for emergency exits, according to the findings. The black symbol 2 (1.60±0.51) with a yellow background had the highest signal intensity (SI) for the magnetic field warning symbol, followed by the black symbol 1 (1.59±0.65) with an orange background. The black symbol 2 (1.59±0.59) with a yellow background and the black symbol 3 (1.58±0.52) with an orange background had the low signal intensity with slight differences as for the radiation zone symbols. In conclusion, it was determined that the signal intensity of the black symbol with a yellow background was the highest in the magnetic field area and radiation area. This implies that symbols with a high signal intensity (SI) must be utilized intensively. To ensure that the correct meaning of the symbols is communicated in the future, they must also be utilized regularly and continually in disaster safety education.

• Journal of the Korean Society of Safety
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• v.15 no.4
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• pp.134-138
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• 2000

Signal words such as DANGER, WARNING, CAUTION, etc. have been used in order to transmit a potential hazard easily and quickly. But they were applied to a number of the sites without consistency. Thus, this study took Quantification Method and Cluster Analysis in order to judge the signal words corresponding to the urgency of situations, and to analyze whether signal words are used properly or not. According to the result of Quantification Method II signal words were most affected by Understanding, Severity and Likelihood in both student group and industrial worker group. And in Quantification Method III CAUTION corresponded to Immediacy and Understanding whereas NOTICE did to Receptivity, WARNING, DEADLY and DANCER did to Likelihood, Dangerousness and Severity. Finally, Cluster Analysis showed that CAUTION and NOTICE were recognized as similar words.

• Current Optics and Photonics
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• v.2 no.5
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• pp.413-421
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• 2018

We propose a novel methodology based on the multiplication function to improve the signal-to-noise ratio (SNR) for vibration detection in a phi optical time-domain reflectometer system (phi-OTDR). The extreme-mean complementary empirical mode decomposition (ECEMD) is designed to break down the original signal into a set of inherent mode functions (IMFs). The multiplication function in terms of selected IMFs is used to determine a vibration's position. By this method, the SNR of a phi-OTDR system is enhanced by several orders of magnitude. Simulations and experiments applying the method to real data prove the validity of the proposed approach.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.3
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• pp.14-27
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• 2020

Pedestrian deaths account for a high percentage of deaths in traffic accidents in Korea, raising interest in pedestrian safety policy. However, since the walk signal time is applied based on the length of the crosswalk without considering the walker and the signal cycle, the walk waiting time is relatively longer than the crosswalk, causing pedestrian jaywalking. In this study, due to an unreasonable signal time plan during a road crossing where a signal is installed, the pedestrian's walk signal was given twice a cycle of crossings, and the operational and safety effects of the signal system were quantitatively and qualitatively analyzed, and the operational effects of the signal interval and jaywalking rate were assessed by different signal intervals. The results showed that jaywalking and waiting time decreased, and the shorter the interval between the application of the walk signal time, the less jaywalking is analyzed. However, there is a risk of vehicle conflict due to pedestrian exposure, and measures for expanding safety for operation were proposed.

• Journal of the Korean Society of Safety
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• v.37 no.2
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• pp.69-75
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• 2022

Fire-alarm systems are safety equipment that facilitate rapid evacuation and early suppression in case of fire. It is highly desirable that fire-alarm systems have low false-alarm rates and are thus reliable. Until now, researchers have attempted to improve detector performance by applying new technologies such as IoT. To this end, IoT-based fire-detection systems have been developed. However, due to scarcity of large-scale operational data, researchers have barely studied malfunctioning in fire-alarm systems or attempted to reduce false-alarm rates in these systems. In this study, we analyzed false-alarm rates of smoke/temperature detectors and unwanted fire-alarm signal patterns at K institution, where Korea's largest IoT-based fire-detection system operates. After analyzing the fire alarm occurrences at the institution for five years, we inferred that the IoT-based fire-detection system showed lower false-alarm rates compared to the automatic fire-detection equipment. We analyzed the detection pattern by dividing it into two parts: normal operation and unwanted fire alarms. When a specific signal pattern was filtered out, the false-alarm rate was reduced to 66.9% in the smoke detector and to 46.9% in the temperature detector.

• Journal of Applied Reliability
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• v.18 no.2
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• pp.153-160
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• 2018

Purpose: A traffic signal controller needs to control and coordinate to ensure that traffic and pedestrians move as smoothly as possible. Since a traffic signal controller has a significant impact on the safety of vehicles and pedestrians, it is important to monitor the failure and deterioration of the traffic signal controller. The purpose of this paper is to propose an IoT (Internet of Things)-based monitoring system for a traffic signal controller. Methods: Every traffic signal controller has a nominal system trajectory specified when it is deployed. The proposed IoT-based monitoring system collects the system trajectory information through real-time monitoring. By comparing the nominal system trajectory and the monitored system trajectory, we are able to detect the failure and deterioration of the traffic signal controller. Conclusion: The proposed IoT-based monitoring system can contribute to the safety of vehicles and pedestrians by maximizing the availability of a traffic signal controller.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.43 no.4 s.310
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• pp.66-73
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• 2006

Safety is the most important for all traffic management and control technology. This paper focuses on developing a flexible, reliable and real-time processing algorithm which is able to generate signal for the entering vehicle at the joining road through a camera and image processing technique. The images obtained from the camera located beside and upon the road can be used for traffic surveillance, the vehicle's travel speed measurement, predicted arriving time in joining area between main road and joining road. And the proposed algorithm displays the confluence safety signal with red, blue and yellow color sign. The three methods are used to detect the vehicle which is driving in setted detecting area. The first method is the gray scale normalized correlation algorithm, and the second is the edge magnitude ratio changing algorithm, and the third is the average intensity changing algorithm The real-time prototype confluence safety signal generation algorithm is implemented on stored digital image sequences of real traffic state and a program with good experimental results.

• Journal of the Korean Society of Safety
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• v.38 no.2
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• pp.36-43
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• 2023

In this study, a four-point bending test was conducted to assess and detect the damage to reinforced concrete structures using the acoustic emission (AE) technique. Based on the crack investigation results, flexural failure was classified into four stages and compared with the characteristic analysis results of AE parameters. The parametric characterization indicated that the activity of the primary AE signal was high in the early stage, and that of the second signal increased after the flexural cracks stabilized. Because the secondary AE signal included noise generated by friction, parameter-based analysis for damage assessment was performed using the primary signal; the secondary signal was used as complement. The activity analyses of the primary and secondary signals effectively classified crack propagation; however, determining the macrocracks and yielding of reinforcing bars had certain limitations. Nevertheless, applying the damage index with cumulative AE energy is a complementary technique for detecting and assessing structure damage that well detects the occurrence of macrocracks.