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Minimum dose path planning for facility inspection based on the discrete Rao-combined ABC algorithm in radioactive environments with obstacles

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Nuclear Science and Techniques 2023年第4期34卷 26-40页

作者： Kwon Ryong Hong Su Il O Ryon Hui kim tae Song kim Jang Su kim Faculty of Energy Science Kim Il Sung UniversityPyongyangDemocratic People’s Republic of Korea High-Tech Research&Development Centre Institute of Information TechnologyKim Il Sung UniversityPyongyangDemocratic People’s Republic of Korea

Workers who conduct regular facility inspections in radioactive environments will inevitably be affected by ***,it is important to optimize the inspection path to ensure that workers are exposed to the least amount of *** study proposes a discrete Rao-combined artificial bee colony(ABC)algorithm for planning inspection paths with minimum exposure doses in radioactive environments with *** this algorithm,retaining the framework of the traditional ABC algorithm,we applied the directional solution update rules of Rao algorithms at the employed bee stage and onlooker bee stage to increase the exploitation ability of the algorithm and implement discretion using the swap operator and swap *** increase the randomness of solution generation,the chaos algorithm was used at the initialization *** K-opt operation technique was introduced at the scout bee stage to increase the exploration ability of the *** path planning in an environment with complex structural obstacles,an obstacle detour technique using a recursive algorithm was *** evaluate the performance of the proposed algorithm,we performed experimental simulations in three hypothetical environments and compared the results with those of improved particle swarm optimization,chaos particle swarm optimization,improved ant colony optimization,and discrete Rao’s *** experimental results show the high performance of the proposed discrete Rao-combined ABC algorithm and its obstacle detour capability.

关键词： Minimum dose Path planning Nuclear facility inspection ABC algorithm Rao algorithms Swap sequence K-opt operation

Enhanced stability and rate performance of zinc-doped cobalt hexacyanoferrate (CoZnHCF) by the limited crystal growth and reduced distortion

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Journal of Energy Chemistry 2022年第6期31卷 649-658,I0018页

作者： Jihwan kim Seong-hoon Yi Li Li Sang-Eun Chun School of Materials Science and Engineering Kyungpook National UniversityDaegu 41566Republic of Korea State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang 110819LiaoningChina School of Metallurgy Northeastern UniversityShenyang 110819LiaoningChina School of Industrial Technology Advances Kyungpook National UniversityDaegu 41566Republic of Korea

Cobalt hexacyanoferrate (CoHCF) is a potential cathode for aqueous Na-ion batteries due to its high theoretical specific capacity (170 m Ah g^(-1));however,its lower rate capability and cyclability limit its *** distortion at a weak N-coordinated crystal field during cycling disintegrates Co,yielding an irreversible *** Zn amounts ranging 0–1 were added to the Co site to suppress the structural irreversibility of CoHCF,yielding Co_(1-x)Zn_(x)HCF powder;this Zn (x≤0.09) addition reduced the powder’s dimension because the lower four coordination of Zn–N,not the six coordination of Co–N,limits the powder ***,a small lattice parameter and interaxial angle (~90°) are obtained,implying that a narrower Co_(1-x)Zn_(x)HCF inner structure is formed to accommodate Na ***,the electronic conductivity of Co_(1-x)Zn_(x)HCF gradually increased within 0–0.09 range.A smaller particle size with a high surface area leads to a near-surface-limited redox process,similar to a capacitive *** the surface-limited reaction and electronic conductivity enhances the reversibility due to the smaller charge transfer resistance at the electrode/electrolyte interface caused by Zn *** redox-active Co with non-active Zn amount of 0.07 (Co_(1-x)Zn_(x)HCF) slightly reduces the specific capacity from 127 to 119 mAh g^(-1)at 0.1 A g^(-1)due to the shrunken Co charging *** performance is enhanced by compromising the capacity and reduced distortion,resulting in 81%retention at a 20-times-faster charging ***,the Co_(1-x)Zn_(x)HCF sample exhibited the good stability while preserving 74%of the initial capacity at 0.5 A g^(-1)after 200 cycles.

关键词： Cobalt hexacyanoferrate Rate capability Stability Growth limitation Structural distortion Near-surface-limited redox process

Bioinspired magnetic cilia:from materials to applications

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Microsystems & Nanoengineering 2023年第6期9卷 107-128页

作者： Seongjin Park Geonjun Choi Minsu Kang Woochan kim Jangho kim hoon Eui Jeong Department of Mechanical Engineering Ulsan National Institute of Science and Technology(UNIST)Ulsan44919Republic of Korea Department of Convergence Biosystems Engineering Chonnam National UniversityGwangju61186Republic of Korea Interdisciplinary Program in IT-Bio Convergence System Chonnam National UniversityGwangju61186Republic of Korea

Microscale and nanoscale cilia are ubiquitous in natural systems where they serve diverse biological *** artificial magnetic cilia have emerged as a highly promising technology with vast potential applications,ranging from soft robotics to highly precise *** this review,we comprehensively discuss the roles of cilia in nature and the various types of magnetic particles utilized in magnetic cilia;additionally,we explore the top-down and bottom-up fabrication techniques employed for their ***,we examine the various applications of magnetic cilia,including their use in soft robotics,droplet and particle control systems,fluidics,optical devices,and ***,we present our conclusions and the future outlook for magnetic cilia research and development,including the challenges that need to be overcome and the potential for further integration with emerging technologies.

关键词： magnetic overcome precise

Finite element analysis using elasto-visco-plastic self-consistent polycrystal model for E-form Mg sheet subjected to bending

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Journal of Magnesium and Alloys 2023年第4期11卷 1393-1407页

作者： Bohye Jeon Min-Seong kim Shi-hoon Choi Youngung Jeong Department of Materials Convergence and System Engineering Changwon National UniversityChangwon-siGyeongnamRepublic of Korea Center for Energy Materials Research Korea Institute of Science and TechnologySeoulRepublic of Korea Department of Advanced Components and Materials Engineering Sunchon National UniversitySuncheon-siJeollanam-doRepublic of Korea School of Materials Science and Engineering Changwon National UniversityChangwon-siGyeongnamRepublic of Korea

The mechanical behavior of a magnesium alloy E-form under bending was investigated using the elasto-visco-plastic polycrystal model(ΔEVPSC) and its finite element(FE) implementation(ΔEVPSC-FE) developed in Jeong et al. and Jeong and Tomé. The crystallographic orientation distribution(COD) obtained from X-ray diffraction was used to represent the initial texture, and the Voce hardening parameters were calibrated by fitting the uniaxial tension and the compression flow stress curves. A quasi-static FE analysis of a miniaturized V-bending operation was conducted using the ΔEVPSC-FE model. The bending induced an inhomogeneous stress response along the through-thickness and the lateral directions, which was well captured by the model. Moreover, the predictive capability of the model was validated by comparing with various experimental results such as(1) force vs. displacement curves;(2) the through-thickness variations in the twin volume fraction;and(3) the changes in crystallographic texture as a function of displacement. Additional bending simulation was performed using an isotropic texture, the result of which suggests that the potential improvement in bendability of the magnesium alloy is attainable by weakening the initial texture. Moreover, the simulation results imply that the crystallographic texture, which may affect the twin activation across the thickness direction, plays a significant role in the shifting direction of the neutral layer.

关键词： FEM Texture V-bending Polycrystal Magnesium Elasto-visco-plasticity

Extrusion limit diagram of AZ91–0.9Ca–0.6Y–0.5MM alloy and effects of extrusion parameters on its microstructure and mechanical properties

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Journal of Magnesium and Alloys 2022年第12期10卷 3447-3458页

作者： Dong HeeLee Ye Jin kim Sang-hoon kim Byoung Gi Moon Sung Hyuk Park School of Materials Science and Engineering Kyungpook National UniversityDaegu 41566Republic of Korea Agency for Defense Development Daejeon 34186Republic of Korea Advanced Metals Division Korea Institute of Materials ScienceChangwon 51508Republic of Korea

An AZ91–0.9Ca–0.6Y–0.5MM(AZXWMM91100) alloy, which has higher corrosion resistance, ignition resistance, and extrudability than a commercial AZ91 alloy, has been developed recently. In this study, the AZXWMM91100 alloy is extruded at various temperatures(300–400 ℃) and ram speeds(1–14.5 mm/s), and the cracking behaviors, microstructure, and tensile properties of the extruded materials are systematically analyzed. On the basis of the pressure limit and surface and internal cracking limit, the extrusion limit diagram providing a safe extrusion processing zone is established. All of the materials extruded at temperatures and speeds within the safe extrusion processing zone have high surface quality and moderate tensile ductility with an elongation higher than 10%. Moreover, they have a fully recrystallized grain structure and contain undissolved particle stringers arranged parallel to the extrusion direction. The grain size of the extruded material does not show any relationship with the Zener–Hollomon parameter(Z). However, the yield strength(YS) of the extruded material is inversely proportional to the logarithm of the Z value, and their relationship is expressed as YS =-31.2·log(Z) + 536. These findings may broaden the understanding of the AZXWMM91100 alloy with excellent chemical and physical properties and provide valuable information for the development of high-performance extruded Mg products using this alloy.

关键词： Magnesium Extrudability Extrusion limit diagram Microstructure Tensile properties

Progress of Materials and Devices for Neuromorphic Vision Sensors

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Nano-Micro Letters 2022年第12期14卷 239-271页

作者： Sung Woon Cho Chanho Jo Yong-hoon kim Sung Kyu Park Department of Electrical and Electronics Engineering Chung-Ang UniversitySeoul 06974Republic of Korea Department of Advanced Components and Materials Engineering Sunchon National UniversitySunchŏnJeonnam 57922Republic of Korea School of Advanced Materials Science and Engineering Sungkyunkwan UniversitySuwon 16419Republic of Korea SKKU Advanced Institute of Nanotechnology(SAINT) Sungkyunkwan UniversitySuwon 16419Republic of Korea

The latest developments in bio-inspired neuromorphic vision sensors can be summarized in 3 keywords:smaller,faster,and smarter.(1)Smaller:Devices are becoming more compact by integrating previously separated components such as sensors,memory,and processing *** a prime example,the transition from traditional sensory vision computing to in-sensor vision computing has shown clear benefits,such as simpler circuitry,lower power consumption,and less data redundancy.(2)Swifter:Owing to the nature of physics,smaller and more integrated devices can detect,process,and react to input more *** addition,the methods for sensing and processing optical information using various materials(such as oxide semiconductors)are evolving.(3)Smarter:Owing to these two main research directions,we can expect advanced applications such as adaptive vision sensors,collision sensors,and nociceptive *** review mainly focuses on the recent progress,working mechanisms,image pre-processing techniques,and advanced features of two types of neuromorphic vision sensors based on near-sensor and in-sensor vision computing methodologies.

关键词： In-sensor computing Near-sensor computing Neuromorphic vision sensor Optoelectronic synaptic circuit Optoelectronic synapse

Distinctive clinical features of spontaneous pneumoperitoneum in neonates: A retrospective analysis

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World Journal of Clinical Cases 2022年第23期10卷 8124-8132页

作者： Soo-Hong kim Yong-hoon Cho Hae-Young kim Department of Surgery Pusan National University Yangsan HospitalPusan National University School of MedicineYangsan 50612South Korea Research Institute for Convergence of Biomedical Science and Technology Pusan National University Yangsan HospitalYangsan 50612South Korea

BACKGROUND Spontaneous pneumoperitoneum(SP) without gastrointestinal perforation rarely occurs in neonates, with most SP cases being idiopathic. Although SP usually follows a benign clinical course with favorable prognosis, it can become lifethreatening in certain situations. In these cases, urgent surgical intervention may be required. Therefore, it may be difficult to decide when or how to perform prompt *** To demonstrate the distinct clinical features of SP to guide appropriate management by comparing characteristics between SP and typical pneumoperitoneum secondary to gastrointestinal *** We retrospectively reviewed electronic medical records and identified 37 neonates with radiological evidence of pneumoperitoneum who were treated at our institution. Clinical variables were compared between neonates with SP without gastrointestinal perforation(Group A) and those with pneumoperitoneum secondary to gastrointestinal perforation(Group B). Clinical variables between groups were compared using Student’s t-test and the chi-square test. The risk factors related to mortality were examined using multi-logistic regression *** Group A comprised 35.1%(13/37) of the patients. The frequency of persistent pulmonary hypertension(53.8%) and pneumothorax(46.2%) before the development of pneumoperitoneum was significantly higher in group A than in group B(P =0.004). Platelet count and partial pressure of arterial oxygen(PaO) were significantly lower in group A(P = 0.015 and 0.025, respectively). Overall mortality was significantly higher in group A than in group B(76.9% vs 16.7%, P = 0.001). Only preterm infants were significantly associated with high mortality(P = 0.041;odds ratio = 18.0). Accompaniment with persistent pulmonary hypertension and pneumothorax were also significantly high(P = 0.004) in group A, but these were not strongly associated with high *** This study identified a higher mortality rate in patients w

关键词： Spontaneous pneumoperitoneum Thrombocytopenia Persistent pulmonary hypertension Pneumothorax Preterm

Topology optimization of reactive material structures for penetrative projectiles

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Defence Technology（防务技术） 2022年第7期18卷 1205-1218页

作者： Shinyu kim Saekyeol kim taekyun kim Sangin Choi tae Hee Lee Jung Su Park Sang-Hyun Jung Department of Automotive Engineering Hanyang University222 Wangsimni-roSeongdong-guSeoul04763Republic of Korea The 4th R&D Institute Agency for Defense Development35Yuseong P.O.BoxDaejeon34186Republic of Korea

Recently,reactive materials have been developed for penetrative projectiles to improve impact resistance and energy ***,the design of a reactive material structure,involving shape and size,is challenging because of difficulties such as high non-linearity of impact resistance,manufacturing limitations of reactive materials and high expenses of penetration *** this study,a design optimization methodology for the reactive material structure is developed based on the finite element analysis.A finite element model for penetration analysis is introduced to save the expenses of the *** resistance is assessed through the analysis,and result is calibrated by comparing with experimental *** on the model,topology optimization is introduced to determine shape of the *** design variables and constraints of the optimization are proposed considering the manufacturing limitations,and the optimal shape that can be manufactured by cold spraying is *** on the optimal shape,size optimization is introduced to determine the geometric dimensions of the *** a result,optimal design of the reactive material structure and steel case of the penetrative projectile,which maximizes the impact resistance,is *** the design process proposed in this study,reactive material structures can be designed considering not only mechanical performances but also manufacturing limitations,with reasonable time and cost.

关键词： Reactive material Penetrative projectile Topology optimization Manufacturing constraint Cold gas dynamic spray Additive manufacturing

OTP-Based Software-Defined Cloud Architecture for Secure Dynamic Routing

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Computers, Materials & Continua 2022年第4期71卷 1035-1049页

作者： tae Woo kim Yi Pan Jong Hyuk Park Department of Computer Science and Engineering Seoul National University of Science and Technology(Seoultech)Seoul01811Korea Department of Computer Science Georgia State UniversityAtlanta30303USA

In the current era,anyone can freely access the Internet thanks to the development of information and communication *** cloud is attracting attention due to its ability to meet continuous user demands for ***,Cloud is effective for systems with large data flow such as the Internet of Things(IoT)systems and Smart ***,the use of traditional networking technology in the cloud causes network traffic overload and network security ***,the cloud requires efficient networking technology to solve the existing *** this paper,we propose one-time password-based software-defined cloud architecture for secure dynamic routing to mitigating the above-mention *** proposed cloud architecture provides a secure data path through dynamic routing using One-Time Internet Protocol(OTIP)algorithm between each *** the network side,we use software-defined technology to provide efficient network management and data *** introduce a software-defined cloud architecture that applies OTIP algorithms for secure dynamic *** conduct a comparative analysis between general IP communication and proposed OTIP communication *** evaluates the performance of OTIP ***,we examine the proposed software-defined cloud architecture,including how to apply OTIP in secure dynamic routing according to the results of the comparative analysis.

关键词： Secure routing dynamic routing one-time password softwaredefined network software-defined perimeter cloud computing