• 제목/요약/키워드: protective systems

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Protective Effect of Modified Glucomannans against Changes in Antioxidant Systems of Quail Egg and Embryo due to Aurofusarin Consumption

  • Dvorska, J.E.;Surai, P.F.
    • Asian-Australasian Journal of Animal Sciences
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    • v.17 no.3
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    • pp.434-440
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    • 2004
  • The aim of this study was to evaluate effects of modified glucomannan ($Mycosorb^{TM}$) on the antioxidant profile of egg yolk and tissues of newly hatched quail after aurofusarin inclusion in the maternal diet. Fifty-four 45 day-old Japanese quail were divided into three groups and were fed a corn-soya diet balanced in all nutrients ad libitum. The diet of the experimental quail was supplemented with aurofusarin at the level of 26.4 mg/kg feed in the form of Fusarium graminearum culture enriched with aurofusarin or with aurofusarin plus $Mycosorb^{TM}$ at 1 g/kg feed. Eggs obtained after 8 weeks of feeding were analysed and incubated in standard conditions of $37.5^{\circ}C$/55% RH. Samples of quail tissues were collected from newly hatched quail. The main carotenoids, retinol, retinyl esters and malondialdehyde were analysed by HPLC-based methods. Inclusion of aurofusarin in the maternal diet was associated with decreased carotenoid and vitamin A concentrations in egg yolk and liver of newly-hatched quail. Furthermore, lipid peroxidation in quail tissues was enhanced. Inclusion of modified glucomannan ($Mycosorb^{TM}$) in the toxin-contaminated diet provided a significant protective effect against changes in antioxidant composition in the egg yolk and liver. It is suggested that a combination of mycotoxin adsorbents and natural antioxidants could be the next step in counteracting mycotoxins in animal feed.

A Study on Operational Characteristics of DC protective relay systems on the Subway (지하철 직류보호계전시스템의 동작특성에 관한 연구)

  • Jung, Hyun-Ki;Jung, Jong-Jin;An, Tae-Pung
    • Proceedings of the KSR Conference
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    • 2008.06a
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    • pp.451-465
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    • 2008
  • The DC over current relay(76i) and the DC under voltage relay(mid-point relay, 80A) used mainly with DC protective relay system of DC electric railway in Korea, But the DC fault selective relay(50F) is applying to recently mainly. In this study, simulation to compare 76i/80A and 50F in the methods of protection and the operational characteristics were executed through verifying a calculation of short circuit current and using PSCAD/EMTDC transition program. As a result of this study, it was proved that while 80A runs in relation to the scale of fault resistance, 50F runs regardless of the scale of fault resistance or the length of rail.

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Analysis of the Protective Distance of Low-Voltage Surge Protective Device(SPD) to Equipment (저압용 서지 보호 장치(SPD)의 보호 거리 해석)

  • Lee, Jung-Woo;Oh, Yong-Taek
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.26 no.4
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    • pp.28-34
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    • 2012
  • Installing surge protection devices for a low-voltage system is important to ensure the survival of electric or electronic devices and systems. If surge protection devices (SPD) are installed without consideration of the concept of lightning protection zones, the equipment to be protected might be damaged despite the correct energy coordination of SPDs. This damage is induced by the reflection phenomena on the cable connecting an external SPD and the load protected. These reflection phenomena depend on the characteristics of the output of the external SPD, the input of the loads, and the cables between the load and the external SPD. Therefore, the SPD has an effective protection distance under the condition of the specific load and the specific voltage protection level of SPD. In this paper, PSCAD/EMTDC software is used to simulate the residual voltage characteristics of SPD Entering the low-voltage device. And by applying a certain voltage level, the effective protection distances of SPD were analyzed according to the each load and length of connecting cable, and the effectiveness of SPD were verified.

Development of an Algorithm for Detecting High Impedance Fault in Low Voltage DC Distribution System using Accumulated Energy of Fault Current (고장전류의 누적 에너지를 이용한 저압직류 배전계통의 고저항 지락고장 검출 알고리즘 개발)

  • Oh, Yun-Sik;Noh, Chul-Ho;Kim, Doo-Ung;Gwon, Gi-Hyeon;Han, Joon;Kim, Chul-Hwan
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.29 no.5
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    • pp.71-79
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    • 2015
  • Recently, new Low Voltage DC (LVDC) power distribution systems have been constantly researched as uses of DC in end-user equipment are increased. As in conventional AC distribution system, High Impedance Fault (HIF) which may cause a failure of protective relay can occur in LVDC distribution system as well. It, however, is hard to be detected since change in magnitude of current due to the fault is too small to detect the fault by the protective relay using overcurrent element. In order to solve the problem, this paper presents an algorithm for detecting HIF using accumulated energy in LVDC distribution system. Wavelet Singular Value Decomposition (WSVD) is used to extract abnormal high frequency components from fault current and accumulated energy of high frequency components is considered as the element to detect the fault. LVDC distribution system including AC/DC and DC/DC converter is modeled to verify the proposed algorithm using ElectroMagnetic Transient Program (EMTP) software. Simulation results considering various conditions show that the proposed algorithm can be utilized to effectively detect HIF.

Double quench and fault current limiting characteristics due to winding ratio of transformer type SFCL with third winding

  • Han, Tae-Hee;Ko, Seok-Cheol;Lim, Sung-Hun
    • Progress in Superconductivity and Cryogenics
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    • v.21 no.3
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    • pp.38-42
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    • 2019
  • To protect the power systems from fault current, the rated protective equipment should be installed. However growth of power system scale and concentration of loads caused the large fault current in power transmission system and distribution system. And capacities of installed protective equipment have been exceeded the due to increase of fault current. This increase is not temporary phenomenon but will be steadily as long as the industry develops. The power system need a counter measurement for safety, so superconducting fault current limiter (SFCL) has been received attention as an effective solutions to reduce the fault current. For the above reasons various type SFCL is studied recently. In this paper, the operational characteristics and power burden of trigger type SFCL is studied. The trigger type SFCL has been used for real system research in many countries. And another trigger type SFCL (double quench trigger type SFCL) is also studied. For this paper, short circuit test is performed.

Development of an Intelligent Control System to Integrate Computer Vision Technology and Big Data of Safety Accidents in Korea

  • KANG, Sung Won;PARK, Sung Yong;SHIN, Jae Kwon;YOO, Wi Sung;SHIN, Yoonseok
    • International conference on construction engineering and project management
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    • 2022.06a
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    • pp.721-727
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    • 2022
  • Construction safety remains an ongoing concern, and project managers have been increasingly forced to cope with myriad uncertainties related to human operations on construction sites and the lack of a skilled workforce in hazardous circumstances. Various construction fatality monitoring systems have been widely proposed as alternatives to overcome these difficulties and to improve safety management performance. In this study, we propose an intelligent, automatic control system that can proactively protect workers using both the analysis of big data of past safety accidents, as well as the real-time detection of worker non-compliance in using personal protective equipment (PPE) on a construction site. These data are obtained using computer vision technology and data analytics, which are integrated and reinforced by lessons learned from the analysis of big data of safety accidents that occurred in the last 10 years. The system offers data-informed recommendations for high-risk workers, and proactively eliminates the possibility of safety accidents. As an illustrative case, we selected a pilot project and applied the proposed system to workers in uncontrolled environments. Decreases in workers PPE non-compliance rates, improvements in variable compliance rates, reductions in severe fatalities through guidelines that are customized according to the worker, and accelerations in safety performance achievements are expected.

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Personal Information life Cycle Model Considering the Learning Cha racteristics of Artificial Intelligence (인공지능의 학습 특성을 고려한 개인정보 라이프 사이클 모델)

  • Jaeyoung Jang;Jong-Min Kim
    • Convergence Security Journal
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    • v.24 no.2
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    • pp.47-53
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    • 2024
  • The traditional personal information life cycle model, primarily tailored to conventional systems, is inherently unsuitable for comprehending the nuances of personal information flow within artificial intelligence frameworks and for formulating effective protective measures. Therefore, this study endeavors to introduce a personal information life cycle model specifically designed for artificial intelligence (AI). This paper presents a personal information life cycle model suitable for artificial intelligence, which includes the stages of collection, retention, learning, use, and destruction/suspension, along with the re-learning process for destruction/suspension. Subsequently, we compare the performance of these existing models (such aspersonal information impact assessment and the ISMS-P model) with the newly proposed model. This underscores the superiority of our proposed model in comprehensively understanding the personal information flow in AI and establishing robust protective measures.

AN APPROACH FOR ESTIMATING TOTAL COST OF OCCUPATIONAL SAFETY FOR BUILDING CONSTRUCTIONS

  • Gurkan Emre Gurcanli;Nesimi Teoman Korkutan;Ugur Mungen
    • International conference on construction engineering and project management
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    • 2011.02a
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    • pp.168-175
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    • 2011
  • Construction accidents are major problem in Turkish Construction industry and especially fatally rates are very high. Current legislative system on occupational safety in Turkey enforces employers to implement safety measures as well as safety management systems. However level of consciousness in the industry is unsatisfactory and safety are perceived as extra cost and unnecessary expenditure. Moreover, especially in small residential building constructions which have a big share in the industry and unfortunately safety measures to mitigate or abate construction risks do not exist. The study focuses on small residential building construction sites and in the scope of this study, thirty building projects are examined. For each building project, project cost including labour and material costs, service and consultancy costs for mechanical, electrical systems as well as architectural and structural services, costs for supervision and finally general expenditures for construction site facilities were calculated. On the other hand, occupational safety costs for personal protective equipment, collective protective measures, consultancy and training were determined. Work breakdown structures were established and for each work item firstly occupational risks were evaluated and furthermore according to risk scores safety measures to be implemented were defined and related costs were calculated. The study gave results for total safety cost on average, in terms of percentage of total project cost (3.73% of total project cost), safety cost per man-hour (0.40 USD) and safety cost in terms of unit construction area (11.60 USD per square meter). Since safety management is a part of whole project management process, study gives suggestions and techniques to calculate safety costs and implement safety measures as a part of project management service for professionals. Authors believe that suggested approach may easily developed by the usage of more data to establish a model for estimation not only for building construction sites but also for all construction projects.

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Lightning Surges Transferred to Low-voltage AC Power Lines through Distribution Transformers (배전용 변압기를 통하여 저압 전원선으로 전파되는 뇌서지)

  • 이복희;이동문;이수봉
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.17 no.4
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    • pp.94-99
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    • 2003
  • A strong need to improve the quality of electric power is increased because of increasing use of the sensitive and small-sized electronic devices. The transient overvoltages on low-voltage AC power distribution systems are induced by direct or indirect lightning return strokes, and they can cause damage and/or malfunction of the utility systems for home automation, office automation and factory automation as well as medical equipment. The behaviors of lightning overvoltages transferred through the transformer to the low voltage AC power distribution systems were experimentally investigated using a Marx generator. The surge voltages in low-voltage ac power systems are rarely limited by the application of the surge arrester to the primary side of distribution transformer and a custom service ground.

Response characteristic of over current relay using optical sensor (광센서를 이용한 과전류 보호계전의 응답특성 연구)

  • 박병석;안성준;조홍근
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.1364-1366
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    • 1997
  • To operate electric power systems economically and stably, and to supply the electric power of good quality, it is necessary that the measured information (current, voltage, and so on) be detected and transmutted with high reliability and high effieincy. For the reason, the optical magnetic field sensor is possible to rapidly detect to over current and recover when electric power line have fault. In addition, the optical sensor have no electro magnetic distortion and no electric insulation. In this study, we designed OCR(Over Current Relay) using optical sensor. The designed OCR using optical sensor was measured characteristic and compared contentional OCR. This system have highest optical advantages and reliability.

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