• Title/Summary/Keyword: Safe

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Safe Speed Estimation of Arctic Ships considering Structural Safety (구조적 안전성을 고려한 빙해선박의 안전 운항속도 평가)

  • Nho, In Sik;Lim, Seung Jae;Kang, Kuk Jin
    • Journal of the Society of Naval Architects of Korea
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    • v.55 no.3
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    • pp.236-242
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    • 2018
  • Damage due to ice collision is the most serious threat for the structural safety of ships operating in arctic region. Since such hull damages are usually caused by the collision of floating ice at excessive voyage speed of ships, the authorities responsible for the shipping at arctic sea are required to provide the speed limit for safe voyage, so-called safe speed. In countries near arctic ocean, such as Canada and Russia, empirical methods to determine the safe speed of ships based on their long experience of arctic voyage have been established and applied them in the real arctic navigation. However, in Korea, it is not easy to accumulate the arctic voyage experience and related technical database, so it seems to be a realistic approach to adopt a safe voyage speed estimating method in arctic sea based on the ice collision simulation technology using the nonlinear finite element analysis. The aim of this study is to develop a technique for estimating the safe voyage speed of vessels operating at arctic sea through the ice collision analysis, In order to achieve this goal, the standard procedure of the ice collision analysis is dealt with and example analysis was carried out and the results were considered. To investigate the validity of developed method, POLARIS system proposed by IMO was studied for comparison.

Safe Adaptive Headlight Controller with Symmetric Angle Sensor Compensator Using Steering-swivel Angle Lookup Table (조향각-회전각 룩업테이블을 이용한 대칭형 각도센서 보상기를 가지는 안전한 적응형 전조등 제어기의 설계)

  • Youn, Jiae;An, Joonghyun;Yin, Meng Di;Cho, Jeonghun;Park, Daejin
    • Transactions of the Korean Society of Automotive Engineers
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    • v.24 no.1
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    • pp.112-121
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    • 2016
  • AFLS (Adaptive front lighting system) is being applied to improve safety in driving automotive at night. Safe embedded system design for controlling head-lamps is required to improve noise robust ECU hardware and software simultaneously by considering safety requirement of hardware-dependent software under severe environmental noise. In this paper, we propose an adaptive headlight controller with a newly-designed symmetric angle sensor compensator, especially based on the proposed steering-swivel angle lookup table to determine whether the current controlling target is safe. The proposed system includes an additional backup hardware to compare the system status and provides safe swivel-angle management using a controlling algorithm based on the pre-defined lookup table (LUT), which is a symmetric mapping relationship between the requested steering angle and expected swivel angle target. The implemented system model shows that the proposed architecture effectively detects abnormal situations and restores safe status of controlling the light-angle in AFLS operations under severe noisy environment.

The Safe Port Warranty Undertaking for Shipowner by Time Charterer -Evidence from the Ocean Victory Case- (국제해운계약상 정기용선자의 선주에 대한 안전항담보의무에 관한 연구 -Ocean Victory호 사건을 중심으로-)

  • HAN, Nak-hyun;JOO, Se-hwan
    • The Journal of shipping and logistics
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    • v.34 no.4
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    • pp.583-613
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    • 2018
  • This study analyse the safe port warranty undertaking for shipowner of time charterer with the Ocean Victory Case. Litigation ensued between those in the charterparty chain. When the hull insurer, Gard, took an assignment of the rights of the vessel's owners and demise charterers in a claim against the time charterers that the vessel had been ordered by them to an unsafe port in breach of the charter. Although the claim succeeded, the Court of Appeal overturned the decision. The Supreme Court delivered its judgment on May 10, 2017, dealing with three important issues, safe port, joint insurance, and limitation of liability. Especially on the safe port issue, the court held that the port was not unsafe within the meaning of the safe port undertaking so the charterers were not in breach of it. The conditions in the port amounted to an abnormal occurrence as that expression is understood.

Factors influencing Healthcare-associated Infection Control of Caregivers (돌봄제공자의 감염관리를 위한 표준주의 이행도 영향요인)

  • Kim, Jeeyoung;Jang, Eunhee
    • Journal of Korean Critical Care Nursing
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    • v.14 no.1
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    • pp.63-75
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    • 2021
  • Purpose : The purposes of this study were to examine the relationships between knowledge, awareness, safe environment, and performance of standard precautions and identify factors associated with performance of standard precautions. Methods : This study was a descriptive research. A structured questionnaire on knowledge, awareness, safe environment, and performance of standard precautions was used for the survey with a convenience sample of 150 caregivers. Data were collected from July to August 2019 and were analyzed using descriptive statistics, independent t-test, one way ANOVA, Pearson's correlation coefficient, and multiple regression with SPSS/WIN 25.0 program. Results : The mean scores on knowledge, awareness, safe environment, and performance of standard precautions were 15.77±3.34, 7.35±1.91, 4.55±2.05, and 55.20±10.11 respectively. Performance of standard precautions showed a statistically significant positive correlation with knowledge (r=.54, p<.001), awareness (r=.54, p<.001), and safe environment (r=.50, p<.001). Awareness (β=.24, p=.025) and safe environment (β=.35, p<.001) were significantly associated with factors of performance of standard precautions. Also, education level (high school and above college), affiliated institution (private association), and importance of infection control education (moderate) were significantly associated with factors of performance of standard precautions. Conclusion : The results of the study indicate that factors influencing the performance of standard precautions of caregivers were awareness and safe environment. Therefore, to improve implementation of the standard precautions among caregivers, a safe environment within the hospital must be supported, and appropriate infection management education needs to be provided to caregivers to improve their knowledge and awareness of the standard precautions.

Development of a Calculation Model for an Optimal Safe Distance between Ship Routes and Offshore Wind Sites (선박 통항로와 해상풍력단지 간 최적의 이격거리 산정 모델 개발)

  • Ohn, Sung-Wook;Namgung, Ho
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.28 no.6
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    • pp.973-991
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    • 2022
  • Globally, several countries with sea are using eco-friendly energy resources through offshore wind power development by overcoming the weak point of the existing power generation method. The sea has the advantage of being able to develop large scale wind farms in wide waters, but the installation of marine structures threatens the safe operation of vessels. Accordingly, a standard guideline for safe navigation by analyzing the mutual effects between ship routes and offshore wind site was presented by the PIANC. Nonetheless, the standard guideline calculated the same safe distance in all situations. Therefore, this study developed a calculation model for an optimal safe distance between ship routes and offshore wind sites by reflecting the ship's maneuvering, encounter situations, environmental force, traffic density, offshore wind power generators, and channel types. As a result of the validation simulation, the developed model showed that the optimal safe distance was secured.

A Study on the Architectural Planning of the Refuge Areas in Geriatric Hospitals Considering Horizontal Evacuation of the Elderly (노인요양병원에서 고령자의 수평 피난을 고려한 대피공간의 건축계획에 관한 연구)

  • Kim, Mijung;Kweon, Jihoon
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.29 no.3
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    • pp.7-15
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    • 2023
  • Purpose: This study was conducted with the aim of presenting spatial planning directions for evacuation spaces based on an analysis of the performance of horizontal evacuation during the early stages of fire incidents in a geriatric hospital. Methods: Based on a review of previous studies, the research model was designed by establishing occupancy conditions, evacuation, and fire scenarios. The analysis model was developed by considering vulnerable areas in terms of evacuation movement and analyzing the results of evacuation performance. Furthermore, the study analyzed the improvement in evacuation performance by arranging refuge areas. Results: The results of the study are as follows. Firstly, vulnerability spots were identified in terms of evacuation performance by schematizing Required Safe Egress Time, Available Safe Egress Time, and their differences. Secondly, the Required Safe Egress Time in the adjacent public spaces along the escape routes of occupants was found to be higher compared to the Available Safe Egress Time. Thirdly, the results of the correlation analysis between the difference in Available Safe Egress Time and Required Safe Egress Time during the early stages of a fire, as well as their constituent factors, demonstrated that user congestion is a more significant factor in compromising evacuation safety than the physical changes in the fire condition. Fourthly, the analysis of evacuation time was conducted by designating refuge areas where occupants can evacuate within a sufficient timeframe. This led to a decrease in the Required Safe Egress Time. Implications: This study is expected to be used as data on the direction of evacuation space planning to improve the evacuation performance of Geriatric Hospital.

A study on the Safe-Life Village Design for the Citizen Security (시민보호를 위한 생활안전 마을지도 설계에 관한 연구)

  • Lee, Tae Shik;Seok, Geum Cheol;Cho, Won Cheol
    • Journal of Korean Society of Disaster and Security
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    • v.6 no.3
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    • pp.43-48
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    • 2013
  • This paper focused on the continuing the citizen safety, the contributing the local economy's activation, and the improving the safe and the social walfare on the civil environment. Seoul metropolitan nominated the model village the Buggaja 2 dong of the Seodaemoon-gu for the making safe village in the 2013. It is designed the village map for the safe life, discovered the dangerous factor about the various and social facilities which is a road, a walking way, a school, a enjoy place for the children, a Thema place, the leasure place, facilities etc., and improved the model village for the incident's and accident's reduction education and training from 2011 to 2013. The results on the discovering and improving activities by the resilient safe monitoring activity, in the 2011 the village is reduced the 23 people from the 151 people to the 128 people in the dead number into the total citizen 34,000 during a year, is showed the excellent values, which the dead people reduced the 23 people in the village, which the safe-life result was over the 12.8% in the national average. For the making resilient city, for the supporting the visitors which it looks around the safe-life model village, the tracking road map is designed, and the tenth safe life factors is showed.

Assessment of Safe Navigation Including the Effect of Ship-Ship Interaction in Restricted Waterways

  • Lee, Chun-Ki
    • Journal of Navigation and Port Research
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    • v.27 no.3
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    • pp.247-252
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    • 2003
  • This paper is mainly concerned with the assessment of safe navigation between ships moving each other in restricted waterways. The numerical simulation of manoeuvring motion was conducted parametrically to propose an appropriate safe speed and distance, which is required to avoid sea accident under the different conditions, such as ship-velocity ratios, ship-length ratios, separation and stagger between ships. As for the calculation parameters, the ratios of velocity difference between two ships were considered as 0.6, 1.2, 1.5 and the ones of ship-length difference were regarded were regarded as 0.5, 1.0, 1.18. From the inspection of this investigation, it indicates the following result. Firstly, the separation between ships is more needed for the small vessel, compared to the large vessel. Secondly, the lateral distance between ships is necessarily required for the velocity ration of 1.2, compared to the cases of 0.6 and 1.5. The manoeuvring characteristics based on this investigation will be very useful for keeping the safety of navigation from the practical point of ships design and traffic control in confined water.

40-TFLOPS artificial intelligence processor with function-safe programmable many-cores for ISO26262 ASIL-D

  • Han, Jinho;Choi, Minseok;Kwon, Youngsu
    • ETRI Journal
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    • v.42 no.4
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    • pp.468-479
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    • 2020
  • The proposed AI processor architecture has high throughput for accelerating the neural network and reduces the external memory bandwidth required for processing the neural network. For achieving high throughput, the proposed super thread core (STC) includes 128 × 128 nano cores operating at the clock frequency of 1.2 GHz. The function-safe architecture is proposed for a fault-tolerance system such as an electronics system for autonomous cars. The general-purpose processor (GPP) core is integrated with STC for controlling the STC and processing the AI algorithm. It has a self-recovering cache and dynamic lockstep function. The function-safe design has proved the fault performance has ASIL D of ISO26262 standard fault tolerance levels. Therefore, the entire AI processor is fabricated via the 28-nm CMOS process as a prototype chip. Its peak computing performance is 40 TFLOPS at 1.2 GHz with the supply voltage of 1.1 V. The measured energy efficiency is 1.3 TOPS/W. A GPP for control with a function-safe design can have ISO26262 ASIL-D with the single-point fault-tolerance rate of 99.64%.

A Study on the Minimum Safe Distance Index of Filipino Navigators in the Vicinity of Obstacles and in Adverse Weather Conditions

  • Dimailig, Orlando S.;Jeong, Jae-Young
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.23 no.3
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    • pp.250-257
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    • 2017
  • This paper investigates minimum safe distances relative to a ship's four cardinal sides, as perceived by Filipino navigators when encountering dangerous elements and in adverse weather conditions when maneuvering in and around harbors. It uses a descriptive research method in the form of a questionnaire survey for experienced Filipino navigators of various ranks. During the course of research, 71 responses were colleted and the resulting data is presented in graphical and tabulated forms. Statistical methods including Pearson-product moment correlations, Cronbach's Alpha and ANOVA were used to identify internal associations, consistencies and significances, respectively. It has been proven that there are no significant differences in minimum safe distances relative to a ship's four cardinal sides, whether maneuvering while approaching a port or within an inner harbor. This study has been deemed significant for training future navigators, managing traffic in fairways, and designing harbors and maneuvering areas in the approaches to ports, among other applications. This work can also be used as a preliminary study for comparison with the well known safe domains presently in use.