• Journal of the Korean Society of Safety
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• v.27 no.5
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• pp.30-34
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• 2012

A safety helmet is a personal protective equipment to protect the head from falling and flying objects. A safety helmet has the maximum delivered impact force as shock absorption performance, the lower delivered impact force the better performance, which was not a controlled variety during manufacturing safety helmet. Accordingly there were some difficulties in establishing the standard for improved performance as there was not a clear controllable impact force for improved performance. In this study the shock absorption performance was intended to be found as coefficient of restitution related to impulse. As a research method, a coefficient of restitution during the absorption of shock was calculated using the impulse transferred to pharynx utilizing the safety helmet shock absorption performance testing device based on the theory of momentum and impulse. The estimated impulsive force curve was derived assuming that shock was not absorbed using the measured data. The sample was selected as tested goods of ABS material for safety certification available mainly in the market. As a result of study, the maximum delivered impact force of safety helmet made by a domestic safety certified a company was 735 N, and its coefficient of restitution proved to be 0.64. The smaller coefficient of restitution is, the lower maximum delivered impact force and the higher shock absorption performance. The coefficient of restitution can be used as a performance index of safety helmet.

• Journal of the Korean Society of Safety
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• v.34 no.6
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• pp.29-37
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• 2019

Since construction sites are exposed to outdoor environments, working conditions are significantly dangerous. Thus, wearing of the personal protective equipments such as safety helmet is very important for worker safety. However, construction workers are often wearing-off the helmet as inconvenient and uncomportable. As a result, a small mistake may lead to serious accident. For this, checking of wearing safety helmet is important task to safety managers in field. However, due to the limited time and manpower, the checking can not be executed for every individual worker spread over a large construction site. Therefore, if an automatic checking system is provided, field safety management should be performed more effectively and efficiently. In this study, applicability of deep learning based computer vision technology is investigated for automatic checking of wearing safety helmet in construction sites. Faster R-CNN deep learning algorithm for object detection and classification is employed to develop the automatic checking model. Digital camera images captured in real construction site are used to validate the proposed model. Based on the results, it is concluded that the proposed model may effectively be used for automatic checking of wearing safety helmet in construction site.

• Journal of the Korean Society of Safety
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• v.38 no.3
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• pp.85-92
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• 2023

A safety helmet is considered the last gear to protect workers from harmful and dangerous events occurring on industrial sites. Recently, interest in the importance of personal protective equipment design reflecting individual characteristics has been emphasized to improve usability and convenience. However, it has been found that if it is inconvenient to wear or has poor work efficiency, it will not be used well or will be used incorrectly. In this study, an investigation was performed with 35 questions, direct observation, and intensive interviews of construction workers to determine the inconvenience and problems of wearing safety helmets. Moreover, managers of 9 construction sites in 6 cities were asked about the performance and design of safety helmets. As a positive answer, it was found that the brim (awning) of the safety helmet was shortened to give the safety glasses a light-shielding function. In addition, an upward adjustment all-in-one type safety helmet was requested. On the other hand, it was revealed that negative answers felt uncomfortable due to the brim (awning) on the front of the helmet. Based on the survey results, a new helmet model suitable for construction site activities was presented, and wearability improvement determinants were discovered through performance and design improvement.

• Journal of the Korean Society of Safety
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• v.27 no.5
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• pp.196-202
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• 2012

An industrial safety helmet primarily intended to protect the wearer's head. It is to prevent or reduce the danger due to flying or dropping objects, falling and prevent the danger due to an electric shock given to the head. However, thermal discomfort of the head is one of the main complaints in the case of wearing safety helmet. Ventilation holes are not allowed in safety helmets on domestic regulations except for industrial safety helmets which are to protect wearer's head against flying or dropping objects. This paper is to produce the need for enlargement of allowing on ventilation holes' regulation to class B. This study reviewed foreign standards' regulations on ventilation holes of safety helmets. Some standards recommend that ventilation may be improved when fresh air is able to enter the helmet around its lower edge and to exit via holes in the helmet located in the upper one third of the helmet. And in the experiments, relationships of ventilation holes and the temperature over the head are analyzed. The experimental results show that the cooling effect of ventilation holes in the upper one third of the helmet is meaningful.

• Design & Manufacturing
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• v.16 no.4
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• pp.7-16
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• 2022

A helmet is essential for safety when operating personal mobility. However, user's actual helmet wear rate is low due to the inconvenience of wearing and poor ventilation. In this study, a new helmet structure with improved ventilation for personal mobility devices was designed. To design a new structure with improved breathability compared to the existing helmet while satisfying the safety regulations for the helmet, a generative design method was applied to the shock-absorbing liner of the helmet. In addition, other materials were applied to create a structure with improved ventilation while maintaining safety. The generated design result was verified for shock absorption through simulation. As a result of the study, EPS, the current material was replaced with CFRP and Kevlar, and the structure was changed. This design was judged to satisfy safety regulations against impact. The new helmet structure is expected to improve the helmet usability for personal mobility and increase the helmet wear rate of users.

• Journal of the Korean Society of Safety
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• v.37 no.6
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• pp.96-101
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• 2022

The Occupational Safety and Health Act holds that industrial safety helmets can be used as protective equipment to prevent the risk of injury in fall accidents. To better understand the importance given to PPE for the head, we analyzed the relevant regulations and guidelines in developed countries and reviewed the guidelines on testing safety helmets. The PPE regulations in Korea were notably different from those in other countries. First, except in Korea and Japan, safety helmets were used for protection against falling objects, flying objects, impact, or electric shock. However, the regulations did not recognize safety helmets as a PPE against fall hazards. Second, the impact energy applied on the helmet was within the range 50-100 J, and the helmet could protect only the upper part of the head against hazards such as the impact of falling objects, flying objects, etc. Third, in Korean regulations, the term "fall" was used in relation to the parts where the safety helmet was specified as a fall hazard PPE, unlike in other countries. We propose that the term "fall" should be revised to "shock" in Korean regulations for the safety helmet.

• Journal of the Korean Institute of Gas
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• v.12 no.4
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• pp.41-45
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• 2008

This paper presents the numerical study on the strength safety and displacement behaviors of a helmet, which is to protect impact forces and to absorb the impact energy. Four different helmet models including a bead frame and a corrugation damper have been analyzed for the stress and the displacement characteristics by using the finite element method. The computed FEM results show that the bead frame on the summit area of the helmet is very useful to increase the strength safety of the helmet, and the corrugation damper on the lower part of the helmet may increase the energy absorption capacity. Thus, this paper recommends the bead frame and the corrugation damper as new design elements of the helmets.

• Journal of the Korea Safety Management & Science
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• v.17 no.3
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• pp.149-162
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• 2015

This study was conducted on young children safety helmet to prevent risk of head injuries from external shock. Young children helmet shall be easy to wear and use comfortably. But the young children helmet market in domestic has imported dependently and widely variations in quality because the euro product of high priced and the east asia product of low priced are selling at the same time. Therefore, this study surveyed children under 13 years of age and Married people and studies their actual state of wearing. Furthermore, this study is going to propese the improving wearing of helmet and the major points of quality of helmet and the problem by comparing and reviewing regulations of domestic and foreign.

• Journal of information and communication convergence engineering
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• v.7 no.4
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• pp.565-569
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• 2009

This paper proposed the safety helmet monitoring system based on USN(Ubiquitous Sensor Networks) to secure the wear of helmet for labor on the construction area. As one of the most significant gear to assure labor's safety, The safety helmet would have the extend of labor's injuries minimized whether one wears or not when an accident takes place. At this point, we have developed and demonstrated the system which is able to check who wear the safety helmet properly for labors, composed of safety helmets with sensor node, router nodes, sink node and management program. Moreover, we could show optimized parameters for the proposed USN system as doing experiment and demonstration, we expected that this system would make for labor wear the safety helmet properly on the construction area as well as prevent economic injury caused by an accident with not wearing for labors.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.3
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• pp.473-482
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• 2022

Wearing a mask is also necessary to limit the risk of infection in today's era of COVID-19 and wearing a helmet is inevitable for the safety of personnel who works in a dangerous working environment such as construction sites. This paper proposes an effective deep learning model, HelmetMask-Net, to classify both Helmet and Mask. The proposed HelmetMask-Net is based on CNN which consists of data processing, convolution layers, max pooling layers and fully connected layers with four output classifications, and 4 classes for Helmet, Mask, Helmet & Mask, and no Helmet & no Mask are classified. The proposed HelmatMask-Net has been chosen with 2 convolutional layers and AdaGrad optimizer by various simulations for accuracy, optimizer and the number of hyperparameters. Simulation results show the accuracy of 99% and the best performance compared to other models. The results of this paper would enhance the safety of personnel in this era of COVID-19.