• Title/Summary/Keyword: Safe zone

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Safety Evaluation of the Lighting at the Entrance of a Very Long Road Tunnel: A Case Study in Ilam

  • Mehri, Ahmad;Hajizadeh, Roohalah;Dehghan, Somayeh Farhang;Nassiri, Parvin;Jafari, Sayed Mohammad;Taheri, Fereshteh;Zakerian, Seyed Abolfazl
    • Safety and Health at Work
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    • v.8 no.2
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    • pp.151-155
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    • 2017
  • Background: At the entrance of a tunnel, reflection of sunlight from the surrounding environment and a lack of adequate lighting usually cause some vision problems. The purpose of this study was to perform a safety evaluation of lighting on a very long road in Ilam, Iran. Methods: The average luminance was measured using a luminance meter (model S3; Hagner, Solna, Sweden). A camera (model 108, 35-mm single-lens reflex; Yashica, Nagano, Japan) was used to take photographs of the safe stopping distance from the tunnel entrance. Equivalent luminance was determined according to the Holliday polar diagram. Results: Considering the average luminance at the tunnel entrance ($116.7cd/m^2$) and using Adrian's equation, the safe level of lighting at the entrance of the tunnel was determined to be 0.7. Conclusion: A comparison between the results of the safe levels of lighting at the entrance of the tunnel and the De Boer scale showed that the phenomenon of black holes is created at the tunnel entrance. This may lead to a misadaptation of the drivers' eyes to the change in luminance level at the entrance of the tunnel, thereby increasing the risk of road accidents in this zone.

Working Principle of a Novel Three-directional Dumping Vehicle and Its Dumping Stability Analysis Under Ground-slope Conditions

  • Kong, Min-kyu;Park, Tusan;Shim, Sung-Bo;Jang, Ik Joo
    • Journal of Biosystems Engineering
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    • v.42 no.4
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    • pp.235-241
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    • 2017
  • Purpose: It is to develop an agricultural three-directional dumping vehicle that can help farmers reduce intensive labor when carrying heavy loads and for easy dumping. In addition, a novel mechanism was applied for controlling the direction of the tilting cargo box by using a single hydraulic cylinder and simple apparatus. The overturning safety was analyzed to provide safe-use ground slope region of the vehicle to be used at upland fields and orchards. Methods: The developed three-directional dumping vehicle was constructed using a cargo box, vehicle frame, driving components, lifting components, and controller. The novel mechanism of controlling the dumping direction involves the operation of two latching bars, which selectively release or collapse the connecting edge between the vehicle frame and cargo box. A multibody dynamics analysis software (RecurDynV8R5) was used to determine the safe-use ground slope area when tilting the cargo box at slopes. A computer analysis was conducted by increasing the ground slope while rotating the vehicle when the cargo box comprised loads of 300 and 500 kg and stacking heights of 40 and 80 cm, respectively. Results: The three-directional dumping vehicle was successfully manufactured, and the cargo box was tilted at $37^{\circ}$ and $35^{\circ}$ for dumping forward and sideways. The latching bars were manually and selectively collapsed with the vehicle frame to control the dumping direction. When forward dumping, the safe-use ground slope was over $20^{\circ}$ in all vehicle directions and loaded conditions. Conclusions: A three-directional dumping vehicle was developed to reduce labor-intensive work in the farming environment. The user can easily control the dumping direction by using the control panel. The vehicle was safe to be used in most of the Korean upland fields and orchards (area over 96%) for the forward dumping.

A Study of Antimicrobial & Antiviral Effect of Natural Product (천연물을 이용한 살균 및 살바이러스 효과에 관한 연구)

  • Ra, Jeong-Chan;Lee, Jong-Eun;Song, Dae-Sub;Kwon, Nam-Hoon;Park, Bong-Kyun;Park, Yong-Ho
    • Journal of Food Hygiene and Safety
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    • v.18 no.4
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    • pp.183-188
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    • 2003
  • Bactericidal effect of $Green-Zone^{(TM)}$ was observed, when Staphylococcus aureus, E. coli O157:H7, Salmonella typhimurium, S. enteritidis, Listeria monocytogenes, the causative bacteria of food poisoning, Vibrio parahaemolyticus, and Shigella sonnei were treated with the diluted solution of $Green-Zone^{(TM)}$(33.3%~4.1%) for 30min at $20^{\circ}C$. All the bacteria were killed in 30 sec, when 33.3%-diluted $Green-Zone^{(TM)}$ was applied, except for S. aureus. Coronavirus, the same virus with SARS virus taxonomically, was also lilled with the 20%-diluted $Green-Zone^{(TM)}$. Canine parvovirus and Canine distermper virus were also killed even in the organic matter and hard water when treated with $Green-Zone^{(TM)}$. When applied to food such as raw fish, chilled meat, vegetables, $Green-Zone^{(TM)}$ could also decrease the number of microorganism, expecially for E. Coli. From these results, $Green-Zone^{(TM)}$ is thought to be effective for killing virus and bacteria, and also was proved to be safe when applied directrly to food.

Evaluation of Bursting Behavior in Anchorage Zone of PSC I Girders (PSC I 거더의 정착부 파열거동 평가)

  • Choi, Kyu Chon;Park, Young Ha;Paik, In Yeol
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.30 no.3A
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    • pp.329-336
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    • 2010
  • An experimental study to evaluate bursting behavior in anchorage zone of the standard PSC I girders (span length : 30 m) has been carried out. The arrangement of bursting reinforcement in anchorage zone of the standard PSC I girders is considered to be designed without accurately reflecting the stress flows in the end zone of the PSC I girders caused by presstressing forces of the tendons. Also, due to excessive arrangement of the bursting bars, the workability of the girder is decreased greatly. In this study, three specimens with the same dimensions as the end zone of the standard PSC I girder are prepared and the experiment is carried out by applying PS forces. The bursting reinforcement of each specimen consists of 100 mm, 200 mm, and 300mm spacings, respectively. The experimental results show that the range of the PS forces to cause crack in the anchorage zone of the specimen are more than 1.6 times of the design PS forces. The bursting cracks occur in the vertical direction on the inside of all specimens. After applying 2.7 times of the design PS force, some of the transverse bursting reinforcements only in the specimen reinforced by 300 mm spacing yielded. The experimental results show that the anchorage zone of the standard PSC I girders arranged by 300 mm spacing of the bursting reinforcements which is the maximum spacing allowed in the road bridge design specifications, can be considered safe enough.

Localization of Mobile Robot In Unstructured Environment using Auto-Calibration Algorithm (Auto-Calibration을 이용한 Unstructured Environment에서의 실내 위치추정 기법)

  • Eom, We-Sub;Seo, Dae-Geun;Park, Jae-Hyun;Lee, Jang-Myung
    • Journal of Institute of Control, Robotics and Systems
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    • v.15 no.2
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    • pp.211-217
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    • 2009
  • This paper proposes a way of expanding the use area of localization technique by using a beacon. In other words, we have developed the auto-calibration algorithm that recognizes the location of this beacon by attaching the beacon on an arbitrary position and by using the information of existing beacon under this situation. By doing so, the moving robot can overcome the limitation that the localization of moving robot is only possible within the area that has installed the existing beacon since the beacon cannot be installed on the accurate location when passing through a danger zone or an unknown zone. Accordingly, the moving robot can slowly move to the unknown zone according to this auto-calibration algorithm and can recognize its own location at a later time in a safe zone. The localization technique is essentially needed in using a moving robot and it is necessary to guarantee certain degree of reliability. Generally, moving robots are designed in a way to work well under the situation that the surroundings is well arranged and the localization techniques of using camera, laser and beacon are well developed. However due to the characteristics of sensor, there may be the cases that the place is dark, interfering radio waves, and/or difficult to install a beacon. The effectiveness of the method proposed in this paper has been proved through an experiment in this paper.

Utilization of induced polarization for predicting ground condition ahead of tunnel face in subsea tunnelling: laboratory test (유도분극을 활용한 해저터널 굴착면 전방 지반상태 예측: 실내실험)

  • Park, Jinho;Lee, Kang-Hyun;Lee, Seong-Won;Ryu, Young-Moo;Lee, In-Mo
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.17 no.3
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    • pp.383-392
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    • 2015
  • In subsea tunnelling, prediction of the fractured zone (or water bearing zone) ahead of tunnel face saturated by seawater with high water pressure has been a key factor for safe construction. This study verified the feasibility of utilizing induced polarization (IP) survey at tunnel face for predicting the ground condition ahead of the subsea tunnel face. A pore model was proposed to compute chargeability in granular material, and the relationship correlating chargeability with the variables affecting the chargeability was derived from the model. Parametric study has been performed on the variables to figure out the most influential factors affecting the chargeability. The results of the parametric study show that the size of narrow pores ($r_1$) and the salinity of pore water are the most influential factors on chargeability. Laboratory tests were conducted on various types of ground condition by changing the salinity of pore water, the thickness of the fracture zone and the existence of gouge (weathered granite) within the joints of the fractured zone to figure out the effect of the ground characteristics on the IP phenomenon. Test results show that the chargeability of the fractured zone saturated by seawater increases if the joints in the fractured zone are filled with gouge since the infilled gouge will decrease the size of narrow pores ($r_1$).

Improvement to Optimum Equipment Model of Agricultural Reservoir Considering Land Mark (랜드마크를 고려한 농업용저수지 최적정비모델의 개선)

  • Kim, Jongbong;Park, So yeon;Jung, Namsu;Lee, Huimang
    • Journal of The Korean Society of Agricultural Engineers
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    • v.62 no.3
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    • pp.63-69
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    • 2020
  • Recently, the Yedang reservoir needs reflecting the demands of the public and administration, including change of reservoir status and paradigm shift of users, as well as planning programs to activate the area as a special health zone for tourism, leisure, recreation and experience at the local government level. Previous Optimum Equipment model (OEM) preferentially considers the creation of waterfront. This study shows the operation model for readjustment of water supply facilities according to the limit of the level of the beneficiaries. Results show the renovation cycle of Yedang tourist resort and the suspension bridge through developed model simulation. In addition to securing quantity for the supply of agricultural water and the function of water protection, the multi-function of the agricultural reservoir shall be re-evaluated to enhance the diverse availability of the agricultural reservoir. The county office should also boost various availability at various levels to revitalize the local economy, such as producing pleasant and safe places and offering safe food for people.

A Study on the Interface between a G7 Pantograph and a KTX Catenary System in Preparation for G7 On-line Tests in the Korea High Speed Test Track (고속 시험선 구간에서의 G7 본선 시운전에 대비한 G7 팬터그래프와 KTX 가선계와의 인터페이스 연구)

  • Cho, Yong-Hyeon;Kyung, Jin-Ho;Hur, Shin;Choe, Kang-youn;Kim, Ki-Hwan
    • Proceedings of the KSR Conference
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    • 2000.11a
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    • pp.557-570
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    • 2000
  • It is necessary to perform a study on the interrace between a G7 pantograph and a KTX catenary system prior to G7 on-line tests in the Korea High Speed Test Track in order to predict how high current collection quality can be obtained during the on-line tests and check if safety problems shall be caused b)Y the tests or not. According to the simulation results, current collection quality of the G7 pantograph at 350km/h is lower than that of a GPU pantograph at 300km/h, but the contact wire uplifts and average contact forces are within the safe-zone. In addition, the ratio of running speed (350km/h) to safe running. Therefore, the G7 on-line tests at 350km/h in the Korea High Speed Test Track is expected not to cause the safety problem.

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A COMPARISON OF OLD AND NEW OSHA REGULATIONS ON CRANES AND DERRICKS USING COMPREHENSIVE GAP ANALYSIS

  • Chung-Suk Cho;Francis Boafo
    • International conference on construction engineering and project management
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    • 2013.01a
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    • pp.74-79
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    • 2013
  • Aiming at reducing deaths and injuries involving construction crane operations, OSHA has recently updated its 40-year-old crane safety standards with new rules addressing the use of cranes and derricks in construction. The goal of this change in rule is to deal with the leading causes of fatalities related to crane and derrick operations. Employers in the construction industry are mandated to ensure that employees in the work zone are trained to recognize hazards associated with the use of the equipment and any related duties that they are assigned to perform. However, those responsible at construction sites for the supervision and management of safe crane operations often lack the integrated knowledge of the standards, regulations and best practices for conducting or supervising daily, monthly, or quarterly inspection of cranes. As such, proper planning, management and implementation of crane operations, including inspections are just as paramount to reducing accidents on the construction site. It is important that engineers responsible for the management and planning of crane operations understand the latest OSHA crane and hoisting standards to ensure a safer work environment is maintained. Many on site engineers overseeing crane operations do not have adequate training, experience, and knowledge of the inspection requirements to assess safe crane operation and too often rely on the crane operator's judgement. This paper highlights recent research effort in defining significant changes in new crane and hoisting standards and provides basis for safety construction operations.

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Running safety of metro train over a high-pier bridge subjected to fluctuating crosswind in mountain city

  • Zhang, Yunfei;Li, Jun;Chen, Zhaowei;Xu, Xiangyang
    • Structural Engineering and Mechanics
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    • v.76 no.2
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    • pp.207-222
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    • 2020
  • Due to the rugged terrain, metro lines in mountain city across numerous wide rivers and deep valleys, resulting in instability of high-pier bridge and insecurity of metro train subjected to fluctuating crosswind. To ensure the safe operation in metro lines in mountain cities, running safety of the metro train over the high-pier bridge under crosswind is analyzed in this paper. Firstly, the dynamic model of the wind-train-bridge (WTB) system is built, in which the speed-up effect of crosswind is fully considered. On the basis of time domain analysis, the basic characteristics of the WTB system with high-pier are analyzed. Afterwards, the dynamic responses varies with train speed and wind speed are calculated, and the safety zone of metro train over a high-pier bridge subjected to fluctuating crosswind in mountain city is determined. The results indicate that, fluctuating crosswind triggers drastic vibration to the metro train and high-pier bridges, which in turn causes running instability of the train. For this reason, the corresponding safety zone for metro train running on the high-pier is proposed, and the metro traffic on the high-pier bridge should be closed as the mean wind speed of standard height reaches 9 m/s (15.6 m/s for the train).