• Title/Summary/Keyword: protective net

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Protection Systems Modeling and Fault Diagnosis of Power System Using Petri Nets (페트리네트를 이용한 전력계통의 보호시스템 모델링과 고장진단)

  • Choi, Jin-Mook;Rho, Myong-Gyun;Hong, Sang-Eun;Oh, Yong-Taek
    • Proceedings of the KIEE Conference
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    • 1999.07c
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    • pp.1136-1138
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    • 1999
  • This paper describes a new method of the modeling of protection system and fault diagnosis in power systems using Petri nets. The Petri net models of protection system are compose of the operating process of protective devices and the fault diagnosis process. Fault diagnosis model which makes use of the nature of Petri net is developed to overcome the drawbacks of methods that depend on operator knowledge. The proposed method can reduce processing time and increase accuracy when compared with the traditional methods. And also this method covers online processing of real-time data from SCADA.

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Modelling Of High Temperature Superconducting Cable Using EMTP-RV and Analysis on the Protective Coordination in Power System (EMTP-RV를 이용한 초전도 케이블 모델링 및 계통 적용 시 보호협조 분석)

  • Ha, Chul-Jong;Baek, Young-Sik;Lee, Geun-Joon;Lee, Hyun-Chul;Yang, Byeong-Mo
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.171_172
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    • 2009
  • 본 논문에서는 EMTP-RV를 이용하여 초전도 케이블과 보호기기를 모델링 하였고, 고장 발생 시 케이블에 발생하는 ��치 현상을 분석하였다. 그리고 계통 적용 시 초전도 케이블을 모선으로 사용하고 보호협조를 분석하였다.

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External dose assessment for workers dismantling the bio-shield of a commercial power nuclear reactor: Case study of Kori-1, Korea

  • Lee, ChoongWie;Lee, Donghyun;Kim, Hee Reyoung;Lee, Seung Jun
    • Nuclear Engineering and Technology
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    • v.52 no.9
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    • pp.2085-2091
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    • 2020
  • The license for Kori-1, the first commercial reactor in Busan, Korea, was terminated in June 2017; therefore, preparations are being made for its decommissioning. Because the radioactivity of Bio-shield varies greatly throughout the structure, the doses received by the workers depend on the location, order, and duration of dismantling operations. Thus, a model for evaluating the worker external dose during the dismantling of the Kori-1 bio-shield was developed, and work scenarios for dose assessment were designed. The Dose evaluation code VISIPLAN was used for dose assessment. The dose rate around the bio-shield was evaluated and the level of exposure to the operator was evaluated according to the work scenario. The maximum annual external dose was calculated as 746.86 mSv for a diamond wire saw operator under dry cutting conditions, indicating that appropriate protective measures, such as changing dismantling sequence, remote monitoring, shield installation, and adjustment of work team are necessary for the safe dismantling of the bio-shield. Through these protective measures, it was found that the worker's dose could be below the dose limit.

Verlamelin, an Antifungal Compound Produced by a Mycoparasite, Acremonium strictum

  • Kim, Jin-Cheol;Park, Gyung-Ja;Kim, Hyun-Ju;Kim, Heung-Tae;Ahn, Jong-Woong;Cho, Kwang-Yun
    • The Plant Pathology Journal
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    • v.18 no.2
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    • pp.102-105
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    • 2002
  • A strain of Acremonium strictum, the mycoparasite of Botrytis cinerea, showed strong antifungal activities both in vitro and in vivo against several phytopathogenic fungi. An antifungal substance was purified from the liquid cultures of A. strictum and identified as verlamelin by instrumental analyses. Verlamelin exhibited in vitro antifungal activity against some phytopathogenic fungi such as Magnaporthe grisea, Bipolaris maydis, and Botrytis cinerea, while it was net active against all the bacteria tested. In viva, verlamelin exhibited strong protective and curative activities, particularly against barley powdery mildew. At 100 μg/ml, it inhibited the development of barley powdery mildew with control values of more than 90% in 7-day protective and 2-day curative applications. This is the first report on the production of verlamelin by Acremonium species.

Application of the new ICRP iodine biokinetic model for internal dosimetry in case of thyroid blocking

  • Kwon, Tae-Eun;Chung, Yoonsun;Ha, Wi-Ho;Jin, Young Woo
    • Nuclear Engineering and Technology
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    • v.52 no.8
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    • pp.1826-1833
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    • 2020
  • Administration of stable iodine has been considered a best measure to protect the thyroid from internal irradiation by radioiodine intake, and its efficacy on thyroid protection has been quantitatively evaluated in several simulation studies on the basis of simple iodine biokinetic models (i.e., three-compartment model). However, the new iodine biokinetic model adopted by the International Commission on Radiological Protection interprets and expresses the thyroid blocking phenomenon differently. Therefore, in this study, the new model was analyzed in terms of thyroid blocking and implemented to reassess the protective effects and to produce dosimetric data. The biokinetic model calculation was performed using computation modules developed by authors, and the results were compared with those of experimental data and prior simulation studies. The new model predicted protective effects that were generally consistent with those of experimental data, except for those in the range of stable iodine administration -72 h before radioiodine exposure. Additionally, the dosimetric data calculated in this study demonstrates a critical limitation of the three-compartment model in predicting bioassay functions, and indicated that dose assessment 1 d after exposure would result in a similar dose estimate irrespective of the administration time of stable iodine.

In-situ measurement of Ce concentration in high-temperature molten salts using acoustic-assisted laser-induced breakdown spectroscopy with gas protective layer

  • Yunu Lee;Seokjoo Yoon;Nayoung Kim;Dokyu Kang;Hyeongbin Kim;Wonseok Yang;Milos Burger;Igor Jovanovic;Sungyeol Choi
    • Nuclear Engineering and Technology
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    • v.54 no.12
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    • pp.4431-4440
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    • 2022
  • An advanced nuclear reactor based on molten salts including a molten salt reactor and pyroprocessing needs a sensitive monitoring system suitable for operation in harsh environments with limited access. Multi-element detection is challenging with the conventional technologies that are compatible with the in-situ operation; hence laser-induced breakdown spectroscopy (LIBS) has been investigated as a potential alternative. However, limited precision is a chronic problem with LIBS. We increased the precision of LIBS under high temperature by protecting optics using a gas protective layer and correcting for shotto-shot variance and lens-to-sample distance using a laser-induced acoustic signal. This study investigates cerium as a surrogate for uranium and corrosion products for simulating corrosive environments in LiCl-KCl. While the un-corrected limit of detection (LOD) range is 425-513 ppm, the acoustic-corrected LOD range is 360-397 ppm. The typical cerium concentrations in pyroprocessing are about two orders of magnitude higher than the LOD found in this study. A LIBS monitoring system that adopts these methods could have a significant impact on the ability to monitor and provide early detection of the transient behavior of salt composition in advanced molten salt-based nuclear reactors.

Conservation of the Old Hat

  • Im Sung-Kyung;Han Myung-Sook
    • The International Journal of Costume Culture
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    • v.7 no.2
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    • pp.151-157
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    • 2004
  • This research is to conservate the old hat and restore its shape and place it on a supportive form in a stable protective container. The hat is a homemade construction, utilizing three different machine made laces, and two cotton net fabrics. The exterior, particularly the top crown piece, as well as the lace along the brim's edge has been generally soiled and discolored. Inside the crown, the cotton net has broken threads, and thread loss in several areas. The paper covering the two wires is very weak, and has discolored the lace in the areas of contact. The plastic buckles of the velvet ribbon have also discolored the areas where there is contact. The wash/bleach bath procedure was very effective. Virtually all of the light brown surface discoloration stains were removed. The darker brown spots, particularly concentrated around the two paper covered wires and assumed to be rust, were $90\%$ removed by the treatment. The brown spots apparently were due to the degradation of the paper covering, and not caused by the wire itself. The buckram foundation lost about $50\%$ of its stiffness, but this was not a major concern due to the fact that this hat should remain it its mount, which has been designed to serve for both storage and exhibition purposes.

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A Fuzzy Continuous Petri Net Model for Helper T cell Differentiation

  • Park, In-Ho;Na, Do-Kyun;Lee, Kwang-H.;Lee, Do-Heon
    • Proceedings of the Korean Society for Bioinformatics Conference
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    • 2005.09a
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    • pp.344-347
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    • 2005
  • Helper T(Th) cells regulate immune response by producing various kinds of cytokines in response to antigen stimulation. The regulatory functions of Th cells are promoted by their differentiation into two distinct subsets, Th1 and Th2 cells. Th1 cells are involved in inducing cellular immune response by activating cytotoxic T cells. Th2 cells trigger B cells to produce antibodies, protective proteins used by the immune system to identify and neutralize foreign substances. Because cellular and humoral immune responses have quite different roles in protecting the host from foreign substances, Th cell differentiation is a crucial event in the immune response. The destiny of a naive Th cell is mainly controlled by cytokines such as IL-4, IL-12, and IFN-${\gamma}$. To understand the mechanism of Th cell differentiation, many mathematical models have been proposed. One of the most difficult problems in mathematical modeling is to find appropriate kinetic parameters needed to complete a model. However, it is relatively easy to get qualitative or linguistic knowledge of a model dynamics. To incorporate such knowledge into a model, we propose a novel approach, fuzzy continuous Petri nets extending traditional continuous Petri net by adding new types of places and transitions called fuzzy places and fuzzy transitions. This extension makes it possible to perform fuzzy inference with fuzzy places and fuzzy transitions acting as kinetic parameters and fuzzy inference systems between input and output places, respectively.

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Risk factors and fisher positioning task during coastal gillnet fishing boat operation using UWB based positioning system (UWB 기반 측위시스템을 이용한 연안자망어선 어선원의 작업위치와 위험요소)

  • Kyung-Jin RYU;Su-Hyung KIM;Kyunghun LEE;Sunghun KIM;Sung-Jae WON;Yoo-Won LEE
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.60 no.2
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    • pp.152-160
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    • 2024
  • We analyzed risk factors of coastal gillnet fishers during fishing process and considered work safety measures to reduce safety accidents during fishing using a UWB (ultra wideband) based positioning system. The static position accuracy of the UWB based positioning system was 45 cm. When entering a port, there is a risk of falling overboard. When casting a net, there was a risk of falling overboard due to being hit by fishing gear or guards, or getting caught in a buoy line or sinker line. When hauling a net, there is a risk of getting caught between fishing gear and net hauler, and the risk of musculoskeletal disorders due to repetitive work over a long period of time. Most safety accidents during work on fishing boats are blamed on human errors of the fisher and skipper, but safety accidents occur due to a mixture of mechanical and equipment factors, work and environmental factors, and management factors in addition to human errors. Therefore, the 4E were presented as countermeasures against the 4M, which are causes of safety accidents, and the proposed measures were used to identify risk factors for operation process, comply with work safety rules, and ensure the wearing of personal protective equipments. We need to reduce safety accidents during work by making it part of our daily routine. These research results can be used in the future for optimal placement of fishing gear and fishing nets in other coastal industries where safety accidents occur frequently.

Copyright and Creativity of Popular Music in the Digital Age: Towards a Sustainable Cultural System

  • Choi, Hwanho
    • International Journal of Contents
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    • v.13 no.3
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    • pp.9-16
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    • 2017
  • The music industry of the digital age has witnessed seemingly endless battles involving copyright. Though continuous efforts to strengthen copyright under romantic understating have benefited major actors in the industry, it has threatened creativity and net activism in the digital age. This study argues rhetoric used by the industry regarding how file sharing and digital environments hurt music sales is inadequate. It has enabled the industry and its major labels to embolden copyright and protective legislation with the government's support. This article will reveal that the issue surrounding copyright under the romantic notion is not an outdated one confined to the early era of digital music This article will argue that major players in the industry are repeating the old strategic approach of controlling the music market. This is achieved by limiting practices of music audiences and future creativity such as the creation of amateur content and emergence of new business models.