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China Foundry 2020年第1期17卷 56-60页

作者： jaehoon choi Hoyoung Hwang Shinill Kang School of Mechanical Engineering Yonsei University50 Yonsei-roSeodaemun-guSeoul03722Korea Digital Manufacturing Process Group Korea Institute of Industrial Technology113-58Seohaean-roSiheung-siGyeonggi-do15014Korea Industrial Technology Korea University of Science and Technology217Gajeong-roYuseong-guDaejeon34113Korea National Center for Optically-assisted Mechanical Systems Yonsei UniversitySeoul03722Korea

This study investigated whether the pouring ladle's outlet shape could reduce the porosity of aluminum alloy casting products and whether it could be applied to mass production of automotive brackets based on computer simulations and *** filling behaviors of the melt were simulated to compare the flow characteristics of the molten metal poured from the conventional ladle and the proposed *** show that for the conventional ladle,the pouring metal is V-shaped,while it is relatively circular and poured at a more constant rate in the proposed *** scans reveal that the proposed ladle reduces the porosity of the cast *** proposed ladle resulted in an average of 30 fewer pores,a 299.56 mm3 smaller average total pore volume,and a 0.041% lower difference in average *** is concludes that the proposed ladle can be used in the gravity casting *** changing the ladle outlet shape can reduce the casting failure rate of massproduced automobile bracket.

关键词： aluminum alloy pouring ladle gravity casting porosity

维普期刊数据库

Mining Botnets and Their Evolution Patterns

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Journal of Computer Science & Technology 2013年第4期28卷 605-615页

作者： jaehoon choi Jaewoo Kang Jinseung Lee Chihwan Song Qingsong Jin Sunwon Lee Jinsun Uh Department of Computer Science and Engineering Korea University Daou Technology Inc.

The botnet is the network of compromised computers that have fallen under the control of hackers after being infected by malicious programs such as trojan viruses. The compromised machines are mobilized to perform various attacks including mass spamming, distributed denial of service （DDoS） and additional trojans. This is becoming one of the most serious threats to the Internet infrastructure at present. We introduce a method to uncover compromised machines and characterize their behaviors using large email logs. We report various spain campaign variants with different characteristics and introduce a statistical method to combine them. We also report the long-term evolution patterns of the spare campaigns.

关键词： bother botnet evolution bother spamming

维普期刊数据库

Ternary layered double hydroxide oxygen evolution reaction electrocatalyst for anion exchange membrane alkaline seawater electrolysis

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Journal of Energy Chemistry 2022年第12期75卷 127-134,I0004页

作者： Yoo Sei Park Jae-Yeop Jeong Myeong Je Jang Chae-Yeon Kwon Geul Han Kim jaehoon Jeong Ji-hoon Lee Jooyoung Lee Sung Mook choi Department of Hydrogen Energy Materials Surface&Nano Materials DivisionKorea Institute of Materials Science(KIMS)Changwon 51508Republic of Korea Department of Advanced Material Engineering Chungbuk National University1 Chungdae-roSeowon-guCheongjuChungbuk 28644Republic of Korea Department of Chemical Engineering University of WaterlooWaterlooOntario N2L 3G1 Canada School of Materials Science and Engineering Gyeongsang National UniversityJinju 52828Republic of Korea Department of Materials Science and Engineering Pusan National UniversityBusan 46241Republic of Korea Energy Industry Support Center Daegu Mechatronics&Materials InstituteDaegu 42704Republic of Korea Advanced Materials Engineering University of Science and Technology(UST)Yuseong-guDaejeon 34113Republic of Korea

Anion exchange membrane(AEM)water electrolyzers are promising energy devices for the production of clean hydrogen from ***,the lack of active and robust electrocatalysts for the oxygen evolution reaction(OER)severely impedes the development of this *** this study,a ternary layered double hydroxide(LDH)OER electrocatalyst(NiFeCo-LDH)is developed for high-performance AEM alkaline seawater *** AEM alkaline seawater electrolyzer catalyzed by the NiFeCo LDH shows high seawater electrolysis performance(0.84 A/cm^(2)at 1.7 Vcell)and high hydrogen production efficiency(77.6%at 0.5 A/cm^(2)),thus outperforming an electrolyzer catalyzed by a benchmark IrO_(2)*** NiFeCo-LDH electrocatalyst greatly improves the kinetics of the AEM alkaline seawater electrolyzer,consequently reducing its activation loss and leading to high *** on the results,this NiFeCo-LDH-catalyzed AEM alkaline seawater electrolyzer can likely surpass the energy conversion targets of the US Department of Energy.

关键词： Anion exchange membranes water electrolysis Oxygen evolution reactions Alkaline seawater electrolysis Hydrogen production

维普期刊数据库

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EL“B”礼堂

城市环境设计 2012年第10期 44-57页

作者： José Selgas Lucía Cano Lara Resco José de Villar José Jaraiz Lorena del Río Blas Antón Miguel San Millán Carlos Chacón Julián Fernandez Beatriz Quintana jaehoon Yook Jeongwoo choi Laura Culianez Bárbara Bardín Iwan Baan Selgascano建筑事务所

EL"B"演艺中心坐落于卡塔赫纳港口,既秉承了原基地的肌理,也充当了城市与大海的边界。码头固有的完美直线、静谧的海平面、平直的甲板以及EL"B"的长条形主体在变幻无常的天空暮景下,融于与自然构建的极简形态中。

关键词： EL 礼堂公共建筑新建筑港口