• Journal of the Korean Institute of Gas
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• v.13 no.4
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• pp.22-26
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• 2009

In this paper, the displacement behavior and strain energy density characteristics of a safety helmet with various corrugation dampers has been analyzed based on the finite element analysis. The safety helmet is to protect impact forces and to absorb the impact energy. Three different helmet models with a corrugation damper have been compared as functions of the displacement and strain energy density characteristics when the maximum external impulsive force is imposed on the summit of the helmet. The computed FEM results show that the extruded corrugation damper is very useful to increase the damping effect of the helmet. This study indicates that the round corrugation damper may absorb the transferred impact energy successfully. Thus, this paper recommends round and long corrugation damper on the lower part of the helmet as a new design element.

• Journal of the Institute of Convergence Signal Processing
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• v.22 no.2
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• pp.57-63
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• 2021

The purpose of this study is to develop a Smart Helmet to safeguard forest firefighting crews and provide on-site information in real time. The Smart Helmet for forest firefingting crews is equipped with a camera, video/voice communication module, GPS, Bluetooth, and LTE module to promote the safety of them, and through the Smart Helmet, the site situation is is transmitted in real time, and full duplex communication is possible. As a result of testing using the Smart Helmet, the control center was able to receive on-site information and communication with on-site forest firefighting crews. Through site evaluation and user evaluation, it was confirmed that the Smart Helmet needs to be improved. The developed Smart Helmet can be used in various ways in forest disasters and forest industry.

• Proceedings of the Korea Information Processing Society Conference
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• 2023.11a
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• pp.826-827
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• 2023

본 연구는 이륜차를 운전함에 있어 기존의 스마트 AR 헬멧과 달리 비대면 음식 배달 서비스 사업에 보다 특화되고 안전에 중점을 둔 스마트 헬멧을 개발하는 방안을 제시하고 있다. 스마트 헬멧, 그리고 본 헬멧과 연동되는 어플리케이션의 개발을 진행하며 웹 대시보드를 통해 라이더의 실시간 위치를 확인하는 기능을 지원한다.

• Journal of the Korean Institute of Gas
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• v.18 no.1
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• pp.68-74
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• 2014

In this study, to analyze the impulsive response of a helmet, a simple vibration model is presented. Based upon the experimental data and the simulation results, an equivalent one degree of freedom vibrational system is adapted, and transient impulsive responses are analysed to investigate the influence of engineering parameters such as damping, natural frequency, and impact velocity on the impulsive response of the helmet. Maximum gravitational acceleration reduces as the damping factor value increases. When the damping factor value is around 0.6 or larger, the maximum acceleration does not change. With respect to the natural frequency and the impact velocity, it increases linearly. The relationship between head injury criterion(HIC) and maximum gravitational acceleration is also presented. The scheme of this study is expected to be utilized to economize the design process of high quality helmets.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.12
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• pp.1569-1575
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• 2012

In this study, ballistic impact effects on a helmet were investigated using the AUTODYN-3D program. Two types of materials were used for manufacturing the helmet: single Kevlar and Steel/Kevlar hybrid composites. Furthermore, two types of bullets were used in the simulation: steel spherical and 7.62 mm full-jacketed. In the simulation, the shape deformation of the projectile and internal energy were calculated. From the results, impact velocities above 655 m/s and 845 m/s were required to perforate the Steel/Kevlar helmet with steel spherical and 7.62 mm full-jacketed bullets, respectively. The results show that there was a large difference between the ballistic resistance of the Kevlar and Steel/Kevlar helmets. For the simulation on an NIJ-STD-0106.01 Type II helmet, a 7.62 mm fulljacketed bullet with a striking velocity of 358 m/s was used. Simulation results show that the Steel/Kevlar helmet could resist a 7.62 mm full-jacketed bullet traveling at 358 m/s.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.7
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• pp.693-701
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• 2010

In this paper, it is proposed that an attitude and position estimation algorithm based on a stereo camera system for a helmet tracker. Stereo camera system consists of two CCD camera, a helmet, infrared LEDs and a frame grabber. Fifteen infrared LEDs are feature points which are used to determine the attitude and position of the helmet. These features are arranged in triangle pattern with different distance on the helmet. Vision-based the attitude and position algorithm consists of feature segmentation, projective reconstruction, model indexing and attitude estimation. In this paper, the attitude estimation algorithm using UQ (Unit Quaternion) is proposed. The UQ guarantee that the rotation matrix is a unitary matrix. The performance of presented algorithm is verified by simulation and experiment.

• Journal of Korean Orthopaedic Sports Medicine
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• v.10 no.2
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• pp.94-99
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• 2011

Purpose: As the number of people enjoying skiing and snowboarding which are two popular winter sports has been increasing, wearing helmet during doing these sports has been needed for safety. The rates of head or face injury have decreased after using helmet. However the effect that wearing helmet has on cervical damage is not yet to be known. So through this research we intend to be helpful in developing effective program and safety equipment. Materials and Methods: During two seasons from December 2009 to march 2011, cased 658 cervical injuries within 14538 admittance in medical center of major resort due to skiing and snow-boarding injuries. For survey and research model, one year before the research year conducted a pilot study. Admittance were 432 male and 226 female, advanced 273 and 385 novice. We divided them into two groups depending on wearing helmet, measured cervical damage ratio and injury mechanism, and researched the severity of damage and diagnosed injury. Each group used SPSS 12.0 (SPSS Inc., Chicago, IL, USA) to process data statistically. Results: The number of patients was 312 in skier and 346 in snow boarder. Patients wearing helmet were 146 in skier and 127 in snow boarder. Classification of each injuries were confirmed as 292 cases of simple sprain, 359 bruising, 6 cervical fractures and 1 case of dislocation. Classification of injury mechanisms were 287 of human collision, 212 material collision, 108 of slip down by oneself, 39 of falling and 12 cases of etc. In cases wearing helmet ski 78/ snow board 70 were simple sprain, ski 64/ snowboard 68 were shown as bruising, ski 1/ snow board 2 had cervical fracture or dislocation. The ratio of cervical sprain increased in cases of wearing helmet compared to non-wearing cases and there was a statistical significance (p<0.001). The ratio of cervical contusion increased significantly in non-wearing helmet user (p<0.05). However, there was no significant increase in fracture and dislocation compared between helmet user and non-user (p> 0.05). Conclusion: In this study, wearing helmet had no relation to additional cervical injury occurrence or severity among skiers and snow boarders. The ratio of cervical sprain increased significantly in helmet user with person to person accident. However, the cervical contusion decreased. On this ground, further biomechanical studies are required and modified helmet will be necessary.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.2
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• pp.123-130
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• 2016

This paper describes the design and implementation scheme of HTS(Helmet Tracking System) providing coincident LOS(Line of Sight) between aircraft and HMD(Helmet Mounted Display) which displays flight and mission information on Pilot helmet. The functionality and performance of HMD system depends on the performance of helmet tracking system. The target of HTS system design is to meet real-time performance and reliability by predicting non-periodic latency and high accuracy performance. To prove an availability of a proposed approach, a robust hybrid scheme with a fusion optical and inertial tracking system are tested through a implemented test-bed. Experimental results show real-time and reliable tracking control in spite of external errors.

• 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.

• The Journal of Korean Society for Radiation Therapy
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• v.33
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• pp.15-24
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• 2021

This study is about the introduction and usefulness evaluation of the manufacturing method of the bolus-helmet. Helmet-production for the treatment of scalp tumor patients has been tried and will continue in many creative and various ways. However, Most of the research data did not significantly reduce the psychological burden and physical and physical discomfort that the patient had to bear due to the time and economic cost required for the production of the helmet, the convenience of production, and the complexity of the process. In addition, recently, studies using more advanced technologies and equipment such as 3D-printer technology, which are being studied as a way to increase the treatment effect, are being introduced, but the time, economic cost, and psychological and physical burden are still the sole responsibility of the patient. Isn't it getting worse? The reality is that the thoughts of concern cannot be erased. Therefore, by maintaining the physical properties of the bolus and manufacturing a helmet without incurring additional costs, the physical and physical discomfort aggravated to the patient was reduced and the procedure and time for helmet manufacturing were minimized. In this way, it was possible to reduce the time, economic cost, and physical discomfort required for the production of the helmet, and it was also possible to minimize the psychological burden of the patient, although it is invisible. Additionally, in evaluating the usefulness of helmets, we are able to continuously seek and develop ways to reduce the air-gap interval, and as a result, we will be able to introduce a method to keep it within 2.0mm along with the manufacturing method through this study. I feel very welcome. Finally, I hope that anyone working in the Department of Radiation Oncology will be able to easily manufacture the helmet required for radiation therapy using a bolus through the guide-line on helmet manufacturing provided by this institute. I hope and hope that if you have any questions or inquiries that arise during the production process, please feel free to contact us through the researcher's e-mail or mobile phone at any time.