• 제목/요약/키워드: distance protection

검색결과 531건 처리시간 0.029초

Negative Trends in Transport-related Mortality Rates in Broiler Chickens

  • Vecerek, Vladimir;Voslarova, Eva;Conte, Francesca;Vecerkova, Lenka;Bedanova, Iveta
    • Asian-Australasian Journal of Animal Sciences
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    • 제29권12호
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    • pp.1796-1804
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    • 2016
  • The high incidence of deaths during transport for slaughter is associated with poor welfare and represents a considerable loss to the poultry industry. In the period from 2009 to 2014, all shipments of broiler chickens to poultry processing plants were monitored in the Czech Republic and the numbers of chickens transported and those dying as a result of their transport were recorded and analysed. Overall transport-related mortality of broiler chickens transported for slaughter in the Czech Republic was 0.37%. It ranged from 0.31% to 0.72%, the increase approximately corresponding to the increasing transport distance. Statistically highly significant (p<0.001) differences were found when comparing transport-related mortality rates in individual seasons of the year. The greatest mortality (0.55%) was associated with transports carried out in winter months whereas the lowest death losses (0.30%) were found in chickens transported for slaughter in summer months. Our study revealed greater transport-related mortality rates in broiler chickens transported for slaughter in the Czech Republic than expected when considering earlier studies. The most pronounced increases were found in transports for shorter distances and in winter months. However, an increase was found at all transport distances monitored except for distances exceeding 300 km and all seasons except for summer. Furthermore, a general increasing tendency in chicken losses during the monitored period was found. The particularly alarming finding is that the mortality of broiler chickens being transported to processing plants has been showing a long-term increasing tendency over the last two decades. Further research should focus on the identification of specific factors leading to such high and growing mortality rates and developing practical guidelines to improve the welfare of the birds in transit accordingly.

Real-time wireless marine radioactivity monitoring system using a SiPM-based mobile gamma spectroscopy mounted on an unmanned marine vehicle

  • Min Sun Lee;Soo Mee Kim;Mee Jang;Hyemi Cha;Jung-Min Seo;Seungjae Baek;Jong-Myoung Lim
    • Nuclear Engineering and Technology
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    • 제55권6호
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    • pp.2158-2165
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    • 2023
  • Marine radioactivity monitoring is critical for taking immediate action in case of unexpected nuclear accidents at nuclear facilities located near coastal areas. Especially when the level of contamination is not predictable, mobile monitoring systems will be useful for wide-area ocean radiation survey and for determination of the level of radioactivity. Here, we used a silicon photomultiplier and a high-efficiency GAGG crystal to fabricate a compact, battery-powered gamma spectroscopy that can be used in an ocean environment. The developed spectroscopy has compact dimensions of 6.5 × 6.5× 8 cm3 and weighs 560 g. We used LoRa, a low-power wireless protocol for communication. Successful data transmission was achieved within 1.4 m water depth. The developed gamma spectroscopy was able to detect radioactivity from a 137Cs point source (3.7 kBq) at a distance of 20 cm in water. Moreover, we demonstrated an unmanned radioactivity monitoring system in a real sea by combining unmanned surface vehicle with the developed gamma spectroscopy. A hidden 137Cs source (3.07 MBq) was detected by the unmanned system at a distance of 3 m. After successfully testing the developed mobile spectroscopy in an ocean environment, we believe that our proposed system will be an effective solution for mobile real-time marine radioactivity monitoring.

EMTP-RV를 이용한 변전소 모선 방식과 보호협조 기초 논리 설계 방법론에 대한 연구 (Design Methodology of the Bus Configuration and Protection Coordination Basic Logics of Power Substation Using EMTP-RV)

  • 고윤석
    • 한국전자통신학회논문지
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    • 제14권6호
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    • pp.1129-1138
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    • 2019
  • 변전소는 변전설비들이 제한된 장소에 집중되어 구조적으로 복잡하기 때문에 송전선로나 배전선로 상에서 고장발생 시 고장파급효과를 최소화하기 위한 보호협조 시스템을 설계하기가 쉽지 않다. 본 연구에서는 변전소 전력공급 신뢰성에 핵심적인 영향을 미치는 모선 방식과 보호협조 기초논리를 분석하였으며 EMTP-RV 기반으로 변전소 내부 및 외부 고장을 정확하게 검출하기 위한 변전소 보호협조 논리를 모델링하였다. 변전소 보호협조 기본 논리로서 변전소 내부 고장 검출을 위한 비율차동 보호계전 논리와 외부고장을 추론하기 위한 과부하 보호계전 논리가 모델링되었다. 끝으로, EMTP-RV를 이용하여 개발된 보호협조 논리 모델링을 기반으로 154kV 변전소를 모델링한 후, 수개의 고장모의를 통해 EMTP-RV 모델링 결과의 유효성을 확인하였다.

ATP시스템에서 열차속도에 따른 지상자에서 차상자로의 자계의 세기에 관한 연구 (A Study on the Magnetic Intensity from Wayside Transmitter to On-board Transmitter about the Train Speed in ATP system)

  • 김민석;고준석;이상혁;김민규;이종우
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2010년도 춘계학술대회 논문집
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    • pp.1841-1848
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    • 2010
  • Electric railway system consist of rolling stock, track, signal and streetcar line system. ATP(Automatic Train Protection) system in railway signaling system is the important one grasping the position and velocity of a train. The wayside transmitter of ATP system is installed between rails. Recently, the research about increasing train speed has been developed in total departments of the railroad systems. The study on the information transmission between on-board transmitter and wayside transmitter is required for increasing the train speed in the ATP system. When the train speed is increased as to same transmissi on distance, the problem on information transmission occurs because the transmission time is decreased. In case that the transmission distance is extended, the transmission time is decreased with respect to the train speed. Therefore, we have to define the standard magnetic intensity as to the train speed in order to transmit correctly telegram. In this paper, the transmission distance for the telegram is suggested on the basis of the train speed. Also, the standard magnetic intensity from the wayside transmitter to on-board transmitter is proposed by using transmission distance regarding the train speed in the ERTMS/ETCS system by using Matlab program.

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화학사고 초기대응 소방대 보호를 위한 독성농도(T-LOC) 끝점거리 연구 (Toxic Concentration(T-LOC) Endpoint Distance Study for Fire Brigade Protection in Response to Chemical Accidents)

  • 윤종찬;조철희;원정훈
    • 한국안전학회지
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    • 제38권6호
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    • pp.60-71
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    • 2023
  • The purpose of this study is to propose a quantitative toxicity endpoint distance suitable for the initial response of firefighters by comparing and analyzing the commonly applied toxic level of concern (T-LOC), specifically emergency response planning guidelines (ERPG), acute exposure guideline levels (AEGL), and immediately dangerous to life or health (IDLH). This is to protect the fire brigade, which responds to toxic chemical accidents first during the golden time. Using areal locations of hazardous atmospheres, a damage prediction program, the amount of leakage for both acidic and basic substances, along with the endpoint distance, were analyzed for alternative accident and worst-case accident scenarios. The results showed that the toxicity endpoint distance, serving as a compromise between Level-3 and Level-2 of T-LOC, was longer than ERPG-3 and shorter than ERPG-2 with IDLH, while its values were analyzed in the order of ERPG-2, AEGL-2, IDLH, AEGL-3, and ERPG-3. It is suggested that the application of IDLH in an emergency (red card) and ERPG-2 endpoint distance in a non-emergency (non-red card) can be utilized for the initial response of the fire brigade.

Energy-efficient Multicast Algorithm for Survivable WDM Networks

  • Pu, Xiaojuan;Kim, Young-Chon
    • Current Optics and Photonics
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    • 제1권4호
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    • pp.315-324
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    • 2017
  • In recent years, multicast services such as high-definition television (HDTV), video conferencing, interactive distance learning, and distributed games have increased exponentially, and wavelength-division multiplexing (WDM) networks are considered to be a promising technology due to their support for multicast applications. Multicast survivability in WDM networks has been the focus of extensive attention since a single-link failure in an optical network may result in a massive loss of data. But the improvement of network survivability increases energy consumption due to more resource allocation for protection. In this paper, an energy-efficient multicast algorithm (EEMA) is proposed to reduce energy consumption in WDM networks. Two cost functions are defined based on the link state to determine both working and protection paths for a multicast request in WDM networks. To increase the number of sleeping links, the link cost function of the working path aims to integrate new working path into the links with more working paths. Sleeping links indicate the links in sleep mode, which do not have any working path. To increase bandwidth utilization by sharing spare capacity, the cost function of the protection path is defined to use sleeping fibers for establishing new protection paths. Finally, the performance of the proposed algorithm is evaluated in terms of energy consumption, and also the blocking probability is evaluated under various traffic environments through OPNET. Simulation results show that our algorithm reduces energy consumption while maintaining the quality of service.

Considerations of the Optimized Protective Action Distance to Meet the Korean Protective Action Guides Following Maximum Hypothesis Accidents of Major KAERI Nuclear Facilities

  • Goanyup Lee;Hyun Ki Kim
    • Journal of Radiation Protection and Research
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    • 제48권1호
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    • pp.52-57
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    • 2023
  • Background: Korea Atomic Energy Research Institute (KAERI) operates several nuclear research facilities licensed by Nuclear Safety and Security Commission (NSSC). The emergency preparedness requirements, GSR Part 7, by International Atomic Energy Agency (IAEA) request protection strategy based on the hazard assessment that is not applied in Korea. Materials and Methods: In developing the protection strategy, it is important to consider an accident scenario and its consequence. KAERI has tried the hazard assessment based on a hypothesis accident scenario for the major nuclear facilities. During the assessment, the safety analysis report of the related facilities was reviewed, the simulation using MELCOR, MACCS2 code was implemented based on a considered accident scenario of each facility, and the international guidance was considered. Results and Discussion: The results of the optimized protective actions were 300 m evacuation and 800 m sheltering for the High-Flux Advanced Neutron Application Reactor (HANARO), the evacuation to radius 50 m, the sheltering 400 m for post-irradiation examination facility (PIEF), 100 m evacuation or sheltering for HANARO fuel fabrication plant (HFFP) facility. Conclusion: The results of the optimized protective actions and its distances for the KAERI facilities for the maximum postulated accidents were considered in establishing the emergency plan and procedures and implementing an emergency exercise for the KAERI facilities.

정보보호 의사결정에서 정보보호 침해사고 발생가능성의 심리적 거리감과 상대적 낙관성의 역할 (The Role of Psychological Distance and Relative Optimism in Information Security Decision Making)

  • 김종기;김지윤
    • 경영정보학연구
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    • 제20권3호
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    • pp.51-71
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    • 2018
  • 많은 정보보호 분야 연구들은 인식을 높여야 할 필요성을 밝히고 있다. 그러나 정보보호에 대한 인식이 상당한 수준으로 높아졌음에도 실제 보호행동은 최근까지 그에 미치지 못하고 있다. 이에 인식수준과는 별개로 정보보호 의사결정에 심리적 요인이 작용할 것으로 가정하고 정보보호에 대한 인식에 차이가 없는 실험상황에서 심리적 거리감과 낙관편향에 따른 차이를 확인하고 정보보호 행동에 대한 영향을 확인하고자 하였다. 연구결과 모바일 기기 사용자의 확률적 거리감에 따라 정보보호 위험의 지각에 차이가 있었으며, 사회적 거리감에 따라 상대적 낙관성의 정도에 차이가 있었다. 이를 바탕으로 상대적 낙관성을 개념화하고 정보보호 행동의도와의 관계를 분석한 결과 자신과 가까운 사람과 비교해 더 낙관적이라 생각했을 때 정보보호 위험의 수준을 낮게 평가하고 확률적 거리감에 따라 영향력이 달라짐을 확인했다. 본 연구는 방법론적 측면에서 의미 있는 시도를 하였고, 정보보호와 관련한 행동에 있어 심리적 요인을 고려함으로써 실질적 위험지각에 영향을 미치는 상대적 낙관성의 범위를 좁혔다는 데 의의가 있다. 정보보호를 위한 의사결정 과정에 다각도로 접근할 필요성을 실증적으로 규명함으로써 궁극적으로 정보기술 사용자의 정보보호 수준 향상과 정보자산의 보호에 기여할 것으로 기대한다.

고속으로 운행하는 고속철도의 소음 방사특성 연구 (A Study on Noise Propagation Properties of Hi-Speed Train)

  • 박태호;한종원;류훈재;고준희;장서일
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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    • pp.2934-2940
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    • 2011
  • The railway system in Korea is developing more and more rapidly. After development the next generation hi-speed train(HEMU-400X), Korea can compete against developed country. But, speed increasing will cause the greater rolling and aero dynamic noise. In this study shows that measurement noise of the KTX train by 300kn/h class, and KTX-Sancheon train by 350km/h class. The measurements are carried out on open area and noise protection barrier installed area. The microphones were placed at a distance of 3m from the center line of the track at a height of 0.5m above the upper surface of the rail and at a distance of 7.5m from the center line of the track at a height of each 0.6m above(Max 3.6m) the upper surface of the rail. One microphone was placed at a distance of 25m for check the environmental noise.

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VDT 작업시 자기장이 인체에 미치는 영향에 관한 연구 (An Effect of Magnetic Field on VDT Work)

  • 박재희;김철중;이남식;김진호
    • 대한인간공학회:학술대회논문집
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    • 대한인간공학회 1992년도 추계학술대회논문집
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    • pp.77-83
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    • 1992
  • The effect of magnetic field on VDT work has not been clarified yet, but many studies repoerted that magnetic field could cause of the cancers. Many developed countries have set the criteria of magnetic field and produce the VDT which has lower magnetic value. The purpose of this study was to measure the intensity of magnectic field from VDT. For this purpose three experiments were performed. The first was designed to measure the intensity of magnetic field by distances(30,60,90 cm) and directions. The second was to compare the intensities between VDT and Color TV. The last was to evaluate the eye protec- tion glasses. The reults showed that the intensity of magnetic field was lowered in proportion to the distance $r^{3}$and both lateral sides of the VDT marked high values compared to the frontal and back sides. On the same distance (30 cm) color TV marked high value to the VDT. But on the normal work distance (TV: 100 cm, VDT: 30 cm) there was little difference, Eye protection glasses could not protect the magnetic field physically.

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