• Title/Summary/Keyword: protective net

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The Analysis on the Validity of Recycling of Vertical Protective Nets Used in Construction Sites (건설현장에서 사용된 수직보호망의 재활용 타당성 분석에 관한 연구)

  • Cho, Hyun-Dae;Jaung, Jae-Dong
    • Journal of the Korea Institute of Building Construction
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    • v.18 no.5
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    • pp.479-488
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    • 2018
  • The issue of waste and its recycling is perceived as a worldwide environmental problem, and the plastic waste is perceived as the biggest social problem threatening the lives of mankind. The vertical protective net, manufactured by using the plastic resin is vertically installed on the outside in case of formwork at the construction site, in order to prevent the fallen objects and scattered dusts. The objective of this study is to understand the actual use status of vertical protective net in the construction site, to examine the changes in the environment-related regulations recently strengthened in the construction site, and also to improve the field technicians' perception of it. And based on it, this study aims to suggest the measures for using the rational and environment-friendly materials and also for promoting the recycling of vertical protective net as the vertical protective nets made of plastic resin are thoughtlessly used in the construction site.

Fuzzy Petri-net Approach to Fault Diagnosis in Power Systems Using the Time Sequence Information of Protection System

  • Roh, Myong-Gyun;Hong, Sang-Eun
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.1727-1731
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    • 2003
  • In this paper we proposed backward fuzzy Petri-net to diagnoses faults in power systems by using the time sequence information of protection system. As the complexity of power systems increases, especially in the case of multiple faults or incorrect operation of protective devices, fault diagnosis requires new and systematic methods to the reasoning process, which improves both its accuracy and its efficiency. The fuzzy Petri-net models of protection system are composed of the operating process of protective devices and the fault diagnosis process. Fault diagnosis model, which makes use of the nature of fuzzy 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 (Supervisory Control and Data Acquisition)

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Growth and Survival of the Spat of Arkshell, Scapharca broughtonii in Intermediate Culture with Different Shape of Protective Net and Type of Preventive Net of Spat Loss (피조개, Scaphara broughtonii 부착치패의 중간양성시 보호망 형태와 유실방지망 종류에 따른 성장과 생존)

  • Kim, Byeong-Hak;Shin, Yun-Kyung;Park, Ki-Yeol;Choi, Nack-Joong;Oh, Bong-Se;Min, Byeong-Hee
    • The Korean Journal of Malacology
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    • v.24 no.2
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    • pp.131-136
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    • 2008
  • Growth and survival of the spat of arkshell, Scapharca broughtonii were investigated for the improvement of survival in intermediate culture with different shape of protective net and type of preventive net of spat loss. The growth performance of the spat of arkshell was observed for 60 days by using different forms of protective net, as the exposure form with an average shell length of $12.8{\pm}3.2$ mm(P<0.05), the fish pot form with $12.2{\pm}3.5$ mm, the cylinder form with $11.9{\pm}3.8$ mm and the last one is the rectangular form with $10.9{\pm}3.7$ mm. Their numerical value did not show any marked difference with each other. But in case of survival rate, the fish pot form showed highest survival rate which is 43.7% and the significantly lowest was showed by the exposure form, which is 5.4%(P<0.05). The cylinder form and rectangular form showed 41.2 and 31.6% respectively. And then the growth of the spat of arkshell was observed for 163 days by rearing in a sort of preventive net, the first group was in a blackout curtain with average shell length of $13.9{\pm}3.1$ mm, the next group was in a balsam pear net with $12.9{\pm}3.0$ mm, in a polyethylene net with $11.8{\pm}3.1$ mm and the control with $12.6{\pm}3.3$ mm which was not installed by preventive net of spat loss. The survival rate was 91.5% in a blackout curtain, 90.1% in a polyethylene net, 88.5% in a balsam pear net and 61.5% in a controlled group. It is seen that the highest growth and survival rate were observed in a fish pot form and cylinder form. These results were a little bit difference from those of the spat of arkshell cultured in the form of different preventive nets. There was no significant difference in survival rate in relation to the sorts of preventive net against carrying-away, but there was a difference in survival rate by more than 30% as against the non-installed controlled group. We expect that survival rate would be highly improved in intermediate culture carried out with fish pot form and cylinder form of protective net and preventive net of spat loss.

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The Effect of Cone Protective Net and the Morphological Variation of Cone and Seed of Korea Rare Endemic Pinus pumila Regel (희귀수종 눈잣나무의 구과보호망 효과 및 구과와 종자의 형태적 변이)

  • Song, Jeong-Ho;Lim, Hyo-In;Jang, Kyung-Hwan;Kim, Du-Hyun;Son, Jang-Ick
    • Korean Journal of Plant Resources
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    • v.25 no.4
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    • pp.401-406
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    • 2012
  • This study was conducted to investigate the effect of cone protective net and the variation of cone and seed characteristics of a unique and rare dwarf stone pine (Pinus pumila Regel) population in Mt. Seorak which is in the southern peripheral of South Korea. Iron protective net (50 mesh, 25 ${\times}$ 25 cm) was effective in reducing birds and rodents damage to conelet, thereby it was possible to safely collect seed genetic resources. Early July was observed to be the most appropriate season to cover conelet with Iron protective net. P. pumila have ovoid-triangle shaped, wingless seeds and indehiscent cones, seeds dissemination is mainly by the hoarding behavior of nutcrackers and rodents. Statistical analysis showed that there were significant differences among individuals within population, and the mean characteristics of the species were 35.3 mm, 25.6 mm, 1.38, 6.6 g and 39.3 ea in the cone length, cone width, cone index, cone weight and in number of seeds per cone, respectively. Coefficients of variations in seed weight and number of seeds per cone were relatively high (21.7%, 21.5%, respectively) compared to other traits. Based on the correlation analysis between cone characteristics and seed characteristics, the length of cone and seed showed a significant positive correlation with the seed size and the seed weight, but the width and thickness of seed showed a negative correlation with the number of seeds per cone.

Catching efficiency of biodegradable trammel net for swimming crab (Portunus trituberculatus) in the Yeonpyeong fishing ground of Korea (연평어장에서 생분해성 꽃게 삼중자망의 어획성능)

  • Kim, In-Ok;Lee, Gun-Ho;Cho, Sam-Kwang;Cha, Bong-Jin;Sohn, Byung-Kyu
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.48 no.4
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    • pp.322-336
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    • 2012
  • To study the catching efficiency of biodegradable trammel net for swimming crab (Portunus trituberculatus), three types (biodegradable, monofilament and multifilament) of trammel nets were used in the field test, and the tests were carried out 16 times with two different mesh sizes (105mm and 160mm) in the Yeonpyeong fishing ground of Korea, 2009~2011. The catching efficiency of three type nets was analyzed by catch in number, catch in weight and average weight per individual of small and large size swimming crab by net types and mesh sizes. Statistical T-test was also carried out to verify the efficiency between the three types of nets. The results are as follows. The catch in number of swimming crab was 24,667 and formed about 81.0% of total catch. Of all swimming crab catch, small swimming crabs with less than 64mm in carapace length which is a prohibited landing size by law formed 48.1%, larger swimming crabs with more than 64mm in carapace length which is a landing size formed 51.9%. In 105mm mesh size trammel net test, the catch share in number of small size swimming crab by biodegradable trammel net was 47.5% in comparison with multifilament trammel net and 74.2% in comparison with monofilament trammel net, so biodegradable trammel net has more protective effects on small size swimming crab than other types of trammel nets. The protective effects for small size swimming crab by biodegradable trammel net was 25.8~52.5% in comparison with other types of trammel nets. The catch share in weight of large size swimming crab by biodegradable trammel net was 98.3% in comparison with multifilament trammel net and 92.3% in comparison with monofilament trammel net, so biodegradable trammel net has a similar catch efficiency to multifilament trammel net. The results of 160mm mesh size trammel net test have shown similar results of 105mm mesh size trammel net test. This study shows that biodegradable trammel net is a more useful fishing gear than multifilament and monofilament trammel net because biodegradable trammel net has lower catch rate than other types of nets in small size swimming crab and similar catch rate than multifilament trammel net which is a well used net by fishermen.

A Study on the characteristics about the Protective Coordination in application of conductive system of Superconductor Cable (배전급 초전도 케이블의 상전도계통 적용시 보호협조 특성연구)

  • Lee, Hyun-Chul;Ryu, Kyung-Woo;Hwang, Si-Dole;Sohn, Song-Ho;Lim, Ji-Hyun;Lee, Geun-Joon
    • Proceedings of the KIEE Conference
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    • 2008.11a
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    • pp.184-186
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    • 2008
  • In this paper, the protective coordination studied in application of HTS cable in conductive system. The protective coordination analyzed to HTS cable using the PSCAD/EMTDC. HTS cable simulated to be appling SFCL or not to be. The result was showed to be protective coordination graph in HTS cable and OCR curve at the power system fault. This graph was proposed to be power operation standard at the HTS cable fault.

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Transmission-Line Wiring Midair Protection Net & Installation Methods (송전선로 가선용 공중설치형 방호네트 및 설치공법)

  • Hwang, Chi-Young;Back, Byoung-Chul;Seo, Min-Geun;Kim, Young-Hwa;Won, Jea-Ho
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.8
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    • pp.1479-1484
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    • 2011
  • The existing leg-rest for transmission line construction was established on the ground as a structure. As a result of that, it caused some problems such as, a tremendous forest damage, excessive construction costs and the long time of construction period. In order to solve these problems, we suggest the protective net for an air installation. It is a new method of construction which has a dielectric strength with a light-weight and high-strength. And it's not influenced by a geographical feature. This excellent method doesn't affect a forest and can reduce tremendously the construction cost and period.

Perception-based analytical technique of evacuation behavior under radiological emergency: An illustration of the Kori area

  • Kim, Jeongsik;Kim, Byoung-Jik;Kim, Namhun
    • Nuclear Engineering and Technology
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    • v.53 no.3
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    • pp.825-832
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    • 2021
  • A simulation-based approach is proposed to study the protective actions taken by residents during nuclear emergencies using cognitive findings. Human perception-based behaviors are not heavily incorporated in the evacuation study for nuclear emergencies despite their known importance. This study proposes a generic framework of perception-based behavior simulation, in accordance with the ecological concept of affordance theory and a formal representation of affordance-based finite state automata. Based on the generic framework, a simulation model is developed to allow an evacuee to perceive available actions and execute one of them according to Newton's laws of motion. The case of a shadow evacuation under nuclear emergency is utilized to demonstrate the applicability of the proposed framework. The illustrated planning algorithm enables residents to compute not only prior knowledge of the environmental map, but also the perception of dynamic surroundings, using widely observed heuristics. The simulation results show that the temporal and spatial dynamics of the evacuation behaviors can be analyzed based on individual perception of circumstances, while utilizing the findings in cognitive science under unavoidable data restriction of nuclear emergencies. The perception-based analysis of the proposed framework is expected to enhance nuclear safety technology by complementing macroscopic analyses for advanced protective measures.

Adaptive undervoltage protection scheme for safety bus in nuclear power plants

  • Chang, Choong-koo
    • Nuclear Engineering and Technology
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    • v.54 no.6
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    • pp.2055-2061
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    • 2022
  • In the event of a short-circuit accident on a 4.16 kV non-safety bus, the voltage is temporarily lowered as backflow occurs on the safety bus. In such cases, the undervoltage relay of the safety bus shall not pick up the undervoltage so as not to interfere with the operation of the safety motors. The aim of this study is to develop an adaptive undervoltage protection scheme for the 4.16 kV safety bus considering the faults on the 13.8 kV and 4.16 kV non-safety buses connected to secondary windings of the three winding transformers, UAT and SAT. The result of this study will be the adaptive undervoltage protection scheme for the safety bus of nuclear power plants satisfying functional requirements of the safety related medium voltage motors. The adaptive undervoltage protection scheme can be implemented into an integrated digital protective relay to make user friendly and reliable protection scheme.

In ovo vaccination using Eimeria profilin and Clostridium perfringens NetB proteins in Montanide IMS adjuvant increases protective immunity against experimentally-induced necrotic enteritis

  • Lillehoj, Hyun Soon;Jang, Seung Ik;Panebra, Alfredo;Lillehoj, Erik Peter;Dupuis, Laurent;Arous, Juliette Ben;Lee, Seung Kyoo;Oh, Sung Taek
    • Asian-Australasian Journal of Animal Sciences
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    • v.30 no.10
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    • pp.1478-1485
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    • 2017
  • Objective: The effects of vaccinating 18-day-old chicken embryos with the combination of recombinant Eimeria profilin plus Clostridium perfringens (C. perfringens) NetB proteins mixed in the Montanide IMS adjuvant on the chicken immune response to necrotic enteritis (NE) were investigated using an Eimeria maxima (E. maxima)/C. perfringens co-infection NE disease model that we previously developed. Methods: Eighteen-day-old broiler embryos were injected with $100{\mu}L$ of phosphate-buffered saline, profilin, profilin plus necrotic enteritis B-like (NetB), profilin plus NetB/Montanide adjuvant (IMS 106), and profilin plus Net-B/Montanide adjuvant (IMS 101). After post-hatch birds were challenged with our NE experimental disease model, body weights, intestinal lesions, serum antibody levels to NetB, and proinflammatory cytokine and chemokine mRNA levels in intestinal intraepithelial lymphocytes were measured. Results: Chickens in ovo vaccinated with recombinant profilin plus NetB proteins/IMS106 and recombinant profilin plus NetB proteins/IMS101 showed significantly increased body weight gains and reduced gut damages compared with the profilin-only group, respectively. Greater antibody response to NetB toxin were observed in the profilin plus NetB/IMS 106, and profilin plus NetB/IMS 101 groups compared with the other three vaccine/adjuvant groups. Finally, diminished levels of transcripts encoding for proinflammatory cytokines such as lipopolysaccharide-induced tumor necrosis $factor-{\alpha}$ factor, tumor necrosis factor superfamily 15, and interleukin-8 were observed in the intestinal lymphocytes of chickens in ovo injected with profilin plus NetB toxin in combination with IMS 106, and profilin plus NetB toxin in combination with IMS 101 compared with profilin protein alone bird. Conclusion: These results suggest that the Montanide IMS adjuvants potentiate host immunity to experimentally-induced avian NE when administered in ovo in conjunction with the profilin and NetB proteins, and may reduce disease pathology by attenuating the expression of proinflammatory cytokines and chemokines implicated in disease pathogenesis.