• Title/Summary/Keyword: safe distance

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Construction of Mine Geospatial Information by Total Station and 3D Laser Scanner (토털스테이션과 3D 레이저 스캐너에 의한 광산공간정보 구축)

  • Park, Joon-Kyu;Lee, Keun-Wang
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.3
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    • pp.520-525
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    • 2019
  • Mines are an important infrastructure for securing resources, but safety problems can arise in the course of operation. Recently, the mining process is very complicated due to the large scale and mechanization. Therefore, it is necessary to construct accurate geospatial information on mine for systematic and safe mine operation. The geospatial information construction using the existing total station has a disadvantage that a lot of work time is required because the target must be collimated and measured. In this study, the data of the mines were acquired with the total station and the 3D laser scanner, and the mine spatial information was constructed by using the shape based registration method. By using the static scanner data of some area applying the reference point surveying result of the total station, it was possible to construct the accurate result on the wide area acquired by the mobile scanner effectively. Also, the accuracy of the constructed geospatial information was evaluated and the deviation of mean 0.083m was shown. Point cloud products constructed through the research can contribute to the efficiency improvement of mine management by enabling quantitative analysis such as visualization of mine shape, distance, area and slope, and automation of drawing creation for cross section shape.

A Study on the Usability Test of People with Disabilities According to the Development of Powered Wheelchair of Standing Support Type (기립보조형 전동휠체어 개발에 따른 장애인 사용성 평가 연구)

  • Rhee, Kun-Min;Kim, Dong-Ok;Hwangbo, Chi-Wook
    • 재활복지
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    • v.20 no.1
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    • pp.211-233
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    • 2016
  • The purpose of this study is to figure out problems and to suggest improvement scheme by examining 31 of the disabled who used power wheelchair developed for safe moving and standing support. The results are as follows. First, standing power wheelchair that enables the disabled to sit and stand up was developed. It can also be used as means of transportation for moving in narrow space and in a short distance. In the usability test of this prototype, two groups were respectively examined in 60 evaluation items. One group consisted of 16 people with disabilities using manual wheelchairs. And the other one consisted of 15 people with disabilities using automatic wheelchairs. The entire average figure of two groups was shown to be 2.72 and standard deviation was 0.820. Specifically, the average figure of the group in manual wheelchair was 2.85 and the one of the other group in automatic wheelchair was 2.57. And both group replied that the move to stand up and sit on both types of wheelchair was the most inconvenient thing. It shows why ergonomic design for persons with under extremity disabilities to stand up and sit is needed. Second, with further study based on the results of usability test of the disabled, it will make contribution to increase the quality of people with disabilities by helping them move and do daily lives on their own.

The Effects of Safety Income System on Recipient's Economic Independence and Life Satisfaction under the Social Security System (사회보장제도의 안심소득제가 수혜자의 경제적 자립과 생활만족에 미치는 영향)

  • Kim, Sung-Ki
    • The Journal of the Korea Contents Association
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    • v.19 no.4
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    • pp.598-608
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    • 2019
  • This study is empirically intended to look into the effects of safety income system on recipient's economic independence and life satisfaction under the social security system. To achieve this, a survey was carried out to 650 adult householders benefiting from the social security system. The SPSS 23 statistical program was used to apply measurement variables related to the safety income system. The results of this study are summarized as follows. The social insurance and the social assistance of safety income system were adopted, having a significant effect on the economic independence. The effect of economic independence on life satisfaction was rejected, while the effect of social assistance on life satisfaction was adopted, showing a difference in the effect of each factor. The findings imply that social insurance and social assistance with support for safe income can be a positive help for economic independence, and unemployment benefit, national pension, long-term care subsidy and health insurance can help to achieve real economic independence, adopting only social assistance with limitation to life satisfaction. Consequently, the safety income system is very useful in helping recipients to achieve their economic independence through its introduction, but there is some distance to meet their life satisfaction.

A Study on Cost Function of Distributed Stochastic Search Algorithm for Ship Collision Avoidance (선박 간 충돌 방지를 위한 분산 확률 탐색 알고리즘의 비용 함수에 관한 연구)

  • Kim, Donggyun
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.25 no.2
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    • pp.178-188
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    • 2019
  • When using a distributed system, it is very important to know the intention of a target ship in order to prevent collisions. The action taken by a certain ship for collision avoidance and the action of the target ship it intends to avoid influence each other. However, it is difficult to establish a collision avoidance plan in consideration of multiple-ship situations for this reason. To solve this problem, a Distributed Stochastic Search Algorithm (DSSA) has been proposed. A DSSA searches for a course that can most reduce cost through repeated information exchange with target ships, and then indicates whether the current course should be maintained or a new course should be chosen according to probability and constraints. However, it has not been proven how the parameters used in DSSA affect collision avoidance actions. Therefore, in this paper, I have investigated the effect of the parameters and weight factors of DSSA. Experiments were conducted by combining parameters (time window, safe domain, detection range) and weight factors for encounters of two ships in head-on, crossing, and overtaking situations. A total of 24,000 experiments were conducted: 8,000 iterations for each situation. As a result, no collision occurred in any experiment conducted using DSSA. Costs have been shown to increase if a ship gives a large weight to its destination, i.e., takes selfish behavior. The more lasting the expected position of the target ship, the smaller the sailing distance and the number of message exchanges. The larger the detection range, the safer the interaction.

Estimation of installation spacing by analyzing the lateral behavior of the safety fence fixed to rail bottom (레일저부고정형 안전펜스의 횡 방향 거동 분석을 통한 설치간격 산정)

  • Park, Seonghyeon;Sung, Deokyong;Lee, Changho;Jung, Hyuksang;Youg, Seungkyong
    • Journal of The Korean Society For Urban Railway
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    • v.6 no.4
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    • pp.249-257
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    • 2018
  • The number of deaths for railway traffic accidents is mainly caused by working close to the track, or when unauthorized passage pass through the track. The safety fences are being used to ensure safety for workers close to the track, and to improve the efficiency of the work, without interfering with the passage of trains. However, a safety fence for railway tracks needs to be examined to see if it will interfere with the passage of trains. The purpose of this study is to analyze the safe distance between train and safety fence developed in Korea. In addition, the lateral load condition of wind pressure by trains is estimated and numerical analysis is carried out according to the installation intervals of railway safety fences. It has been confirmed that the proper spacing between the train and the railway safety fence should be at least 200 mm from the vehicle limit, and that the proper spacing of railway safety fence must be calculated in consideration of the wind pressure by trains.

A Study on Dam Exterior Inspection and Cost Standards using Drones (드론을 활용한 댐 외관조사 및 대가기준에 대한 연구)

  • Kim, Tae-Hoon;Lee, Jai-Ho;Kim, Do-Seon;Lee, Suk-Bae
    • Journal of the Society of Disaster Information
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    • v.17 no.3
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    • pp.608-616
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    • 2021
  • Purpose: Safety inspections by existing personnel have been limited in evaluation and data securing due to concerns about the safety of technicians or difficulty in accessing them, and are becoming a bigger problem as the number of maintenance targets increases due to the aging of facilities. As drone technology develops, it is possible to ensure the safety of personnel, secure visual data, and diagnose quickly, and use it is increasing as safety inspection of facilities by drones was introduced recently. In order to further enhance utilization, it is considered necessary to base a consideration standard for facility appearance investigation by drones, and in this paper, research was conducted on dams. Method: To calculate the quality, existing domestic safety inspection and drone-related consideration standards were investigated, and procedures related to safety inspection using drones were compared and analyzed to review work procedures and construction types. In addition, empirical data were collected through drone photography and elevation image production for the actual dam. Result: Work types for safety inspection of facilities using drones were derived, and empirical survey results were collected for two dams according to work types. The existing guidelines were applied for the adjustment ratios for each structural type and standard of the facility, and if a meteorological reference point survey was necessary, the unmanned aerial vehicle survey of the construction work standard was applied. Conclusion: The finer the GSD in appearance investigation using drones, the greater the number of photographs taken, and the concept of adjustment cost was applied as a correction to calculate the consideration standard. In addition, it was found that the problem of maximum GSD indicating limitations should be considered in order to maintain the safe distance.

A Study of Hazard Analysis and Monitoring Concepts of Autonomous Vehicles Based on V2V Communication System at Non-signalized Intersections (비신호 교차로 상황에서 V2V 기반 자율주행차의 위험성 분석 및 모니터링 컨셉 연구)

  • Baek, Yun-soek;Shin, Seong-geun;Ahn, Dae-ryong;Lee, Hyuck-kee;Moon, Byoung-joon;Kim, Sung-sub;Cho, Seong-woo
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.19 no.6
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    • pp.222-234
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    • 2020
  • Autonomous vehicles are equipped with a wide rage of sensors such as GPS, RADAR, LIDAR, camera, IMU, etc. and are driven by recognizing and judging various transportation systems at intersections in the city. The accident ratio of the intersection of the autonomous vehicles is 88% of all accidents due to the limitation of prediction and judgment of an area outside the sensing distance. Not only research on non-signalized intersection collision avoidance strategies through V2V and V2I is underway, but also research on safe intersection driving in failure situations is underway, but verification and fragments through simple intersection scenarios Only typical V2V failures are presented. In this paper, we analyzed the architecture of the V2V module, analyzed the causal factors for each V2V module, and defined the failure mode. We presented intersection scenarios for various road conditions and traffic volumes. we used the ISO-26262 Part3 Process and performed HARA (Hazard Analysis and Risk Assessment) to analyze the risk of autonomous vehicle based on the simulation. We presented ASIL, which is the result of risk analysis, proposed a monitoring concept for each component of the V2V module, and presented monitoring coverage.

Changes in School Foodservice during COVID-19 Pandemic Lockdown based on Focus Group Interviews (포커스 그룹 인터뷰를 통한 COVID-19 유행 동안 학교 급식의 변화)

  • Ji, Mirim;Um, Mihyang;Kye, Seunghee
    • Journal of the Korean Society of Food Culture
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    • v.37 no.1
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    • pp.1-12
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    • 2022
  • This qualitative study analyzed various environmental factors and difficulties faced by school foodservices during the COVID-19 pandemic. Focus group interviews were conducted by enrolling 12 nutrition teachers and nutritionists. Data collected were subsequently analyzed for changes implemented during the pandemic, in hygiene management, diet management, and distribution management of the school meal. The content and method of delivery of information related to diet guidance and school foodservice by related organizations were also examined. Results of the survey show that personal hygiene (such as maintaining student-to-student distance, checking students for a fever, and hand disinfection) was duly applied, installation of table coverings and distancing between school cafeteria seats were conducted, and mandatory mask-wearing to prevent droplet transmission was enforced. Depending on the COVID-19 situation, the number of students having school meals was limited per grade, and time-spaced meals were provided. To prevent infection, menus that required frequent hand contact were excluded from the meal plan. Overall, it was difficult to manage the meal plan due to frequent changes in tasks, such as the number of orders and meal expenses. These changes were communicated by nutrition teachers and nutritionists wherein the numbers of school meals were adjusted, depending on situations arising from each COVID-19 crisis stage. Furthermore, in some schools, either face-to-face nutrition counseling was stopped entirely, or nutrition education was conducted online. Parent participation was disallowed in the monitoring of school meals, and the prohibition on conversations inside the school cafeteria resulted in the absence of communication among students, nutrition teachers, and nutritionists. Additionally, confusion in meal management was caused by frequent changes in the school meal management guidelines provided by the Office of Education and the School Health Promotion Center in response to COVID-19. In anticipation of the emergence of a new virus or infectious diseases caused by mutations in the years to come, it is suggested that a holistic, well-thought-out response manual for safe meal operation needs to be established, in close collaboration with schools and school foodservice-related institutions.

Study in the Development of Motion Recognition Tap-water using Ultrasonic Sensors (초음파 센서를 이용한 모션 인식 수도꼭지 개발 및 연구)

  • Kim, Dong-Hyun;Ryu, Jae-Hoo;Ju, Jong-Soo;Ahn, Jong-Pil;Kim, Jae-Wook
    • The Journal of the Korea institute of electronic communication sciences
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    • v.17 no.2
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    • pp.309-316
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    • 2022
  • Advances in technology have improved people's lives comfortably and have developed more easily, safely and simply. We usually turn on hot water to set the temperature of the water in the bathroom and gradually adjust the temperature to find the temperature we want with our skin. In this situation, I thought, "What if there is a device that can see the temperature of water with my eyes and help with the interior of the bathroom while including a safe system," and tried to create a system that values stability. For example, if a child accidentally changes the temperature of the water to high temperature while washing, he or she can get burned. And the biggest purpose is to secure better safety by adding LCDs and LEDs so that we can visually know the temperature before feeling it tactilely. As a result of the experiment, there was no error between the temperature detected by the water temperature sensor and the temperature displayed on the LCD, and no error occurred up to 27 cm in the distance measurement experiment using the ultrasonic sensor. There has been an error of about 2% since 28cm or older, but there is no significant inconvenience in using it within the category of faucets.

Study on Advisory Safety Speed Model Using Real-time Vehicular Data (실시간 차량정보를 이용한 안전권고속도 산정방안에 관한 연구)

  • Jang, JeongAh;Kim, HyunSuk
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.30 no.5D
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    • pp.443-451
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    • 2010
  • This paper proposes the methodology about advisory safety speed based on real-time vehicular data collected from highway. The proposed model is useful information to drivers by appling seamless wireless communication and being collected from ECU(Engine Control Unit) equipment in every vehicle. Furthermore, this model also permits the use of realtime sensing data like as adverse weather and road-surface data. Here, the advisory safety speed is defined "the safety speed for drivers considering the time-dependent traffic condition and road-surface state parameter at uniform section", and the advisory safety speed model is developed by considering the parameters: inter-vehicles safe stopping distance, statistical vehicle speed, and real-time road-surface data. This model is evaluated by using the simulation technique for exploring the relationships between advisory safety speed and the dependent parameters like as traffic parameters(smooth condition and traffic jam), incident parameters(no-accident and accident) and road-surface parameters(dry, wet, snow). A simulation's results based on 12 scenarios show significant relationships and trends between 3 parameters and advisory safety speed. This model suggests that the advisory safety speed has more higher than average travel speed and is changeable by changing real-time incident states and road-surface states. The purpose of the research is to prove the new safety related services which are applicable in SMART Highway as traffic and IT convergence technology.