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Computers, Materials & Continua 2021年第1期66卷 59-70页

作者： Sangmi MoonHyeonsung Kim Seng-phil Hong Mingoo Kang Intae Hwang Department of Electronic Engineering Chonnam National UniversityGwangju61186Korea Hancom With Inc. Seongnam-si13493Korea Division of Information&Telecommunication Hanshin UniversityOsan-si18101Korea

Millimeter-wave communications are suitable for application to massive multiple-input multiple-output systems in order to satisfy the ever-growing data traffic demands of the next-generation wireless ***,their practical deployment is hindered by the high cost of complex hardware,such as radio frequency(RF)*** this end,operation in the beamspace domain,through beam selection,is a viable ***,the conventional beam selection schemes focus on the feedback and exhaustive search *** addition,since the same beam in the beamspace may be assigned to a different user,conventional beam selection schemes suffer serious multi-user *** addition,some RF chains may be wasted,since they do not contribute to the sum-rate ***,a fingerprint-based beam selection scheme is proposed to solve these *** proposed scheme conducts offline group-based fingerprint database construction and online beam selection to mitigate multi-user *** the offline phase,the contributing users with the same best beam are *** grouping,a fingerprint database is created for each *** the online phase,beam selection is performed for purposes of interference mitigation using the information contained in the group-based fingerprint *** simulation results confirm that the proposed beam selection scheme can achieve a signal-to-interference-plus-noise ratio and sum-rate performance which is close to those of a fully digital system,and having much higher energy efficiency.

关键词： Beam selection beamspace group-based fingerprint interference mitigation millimeter-wave

Data Traffic Reduction with Compressed Sensing in an AIoT System

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Computers, Materials & Continua 2022年第1期70卷 1769-1780页

作者： Hye-Min Kwon Seng-phil Hong Mingoo Kang Jeongwook Seo Hanshin University Osan-si18101Korea Hancom with Inc. Seongnam-si13493Korea

To provide Artificial Intelligence(AI)services such as object detection,Internet of Things(IoT)sensor devices should be able to send a large amount of data such as images and ***,this inevitably causes IoT networks to be severely *** this paper,therefore,we propose a novel oneM2M-compliant Artificial Intelligence of Things(AIoT)system for reducing overall data traffic and offering object *** consists of some IoT sensor devices with random sampling functions controlled by a compressed sensing(CS)rate,an IoT edge gateway with CS recovery and domain transform functions related to compressed sensing,and a YOLOv5 deep learning function for object detection,and an IoT *** analyzing the effects of compressed sensing on data traffic reduction in terms of data rate per IoT sensor device,we showed that the proposed AIoT system can reduce the overall data traffic by changing compressed sensing rates of random sampling functions in IoT sensor *** addition,we analyzed the effects of the compressed sensing on YOLOv5 object detection in terms of performance metrics such as recall,precision,mAP50,and mAP,and found that recall slightly decreases but precision remains almost constant even though the compressed sensing rate decreases and that mAP50 and mAP are gradually degraded according to the decreased compressed sensing ***,if proper compressed sensing rates are chosen,the proposed AIoT system will reduce the overall data traffic without significant performance degradation of YOLOv5.

关键词： 5G Internet of Things data traffic compressed sensing YOLOv5

Study on SCR De NO_x mechanism through in situ electrical conductivity measurements on V_2O_5-WO_3/TiO_2 catalysts

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Rare Metals 2006年第z2期25卷 77-83页

作者： HA Heon phil JUNG Soon Hyo LEE Jun Yub HONG Sung Ho Metal Processing Research Center Korea Institute of Science and Technology Cheongryang Seoul 130-650 Republic of Korea Power Engineering Research Institute Korea Power Engineering Company Inc. 360-9 Mabuk-ri Guseong-eup Yongin-si Gyeonggi-do 449-713 Republic of Korea

V2O5-WO3/TiO2 catalysts were prepared by impregnation method and in situ electrical conductivity measurements were carried out to investigate the reaction mechanism for ammonia SCR (selective catalytic reduction) of NOx. The electrical conductivity change with ammonia supply and the increase of electrical conductivity were mainly caused by reduction of the labile surface oxygen. The electrical conductivity change of catalysts shows close relationship with the conversion rate of NOx. Variation of conversion rate in atmosphere without gaseous oxygen also supports that the labile lattice oxygen is indispensable in the initial stage of the de NOx reaction. These results suggest that the liable lattice oxygen acts decisive role in the de NOx mechanism. They also support that De NOx reaction occurs through the Eley-Rideal type mechanism. The amount of labile oxygen can be estimated from the measurement of electrical conductivity change for catalysts with ammonia supply.

关键词： De NOx selective catalytic reduction electrical conductivity lattice oxygen

Further-Adjusted Long-Term Temperature Series in China Based on MASH

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Advances in Atmospheric Sciences 2018年第8期35卷 13-21页

作者： Zhen LI Zhongwei YAN Lijuan CAO phil D. JONES Key Laboratory of Regional Climate-Environment in Temperate East Asia Institute of Atmospheric Physics Beijing 100029 China University of the Chinese Academy of Sciences Beijing 100049 China National Meteorological Information Center China Meteorological Administration Beijing 100081 China Climatic Research Unit University of East Anglia Norwich Norfolk NR4 7TJ United Kingdom Center of Excellence for Climate Change Research/Department of Meteorology King Abdulaziz University Jeddah 21589 Saudi Arabia

A set of homogenized monthly mean surface air temperature （SAT） series at 32 stations in China back to the 19th century had previously been developed based on the RHtest method by Cao et al., but some inhomogeneities remained in the dataset. The present study produces a further-adjusted and updated dataset based on the Multiple Analysis of Series for Homogenization （MASH） method. The MASH procedure detects 33 monthly temperature records as erroneous outliers and 152 meaningful break points in the monthly SAT series since 1924 at 28 stations. The inhomogeneous parts are then adjusted relative to the latest homogeneous part of the series. The new data show significant warming trends during 1924-2016 at all the stations, ranging from 0.48 to 3.57℃ （100 yr）^-1, with a regional mean trend of 1.65℃ （100 yr）^-1 ; whereas, the previous results ranged from a slight cooling at two stations to considerable warming, up to 4.5℃ （100 yr）^-1. It is suggested that the further-adjusted data are a better representation of the large-scale pattern of climate change in the region for the past century. The new data axe available online at http：//***/10.11922/sciencedb.516.

关键词： homogenization Multiple Analysis of series for homogenization (MASH) monthly temperature series long-term trend China

Preparation of AZ91D Slurries for Semi-Solid Forming Using Al8 ( Mn, Fe) 5 Precipitates

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Journal of Rare Earths 2004年第z2期22卷 42-46页

作者： Ji Young Byun Soon Il Kwon Jeong Man Doh Heon phil Ha Metal Processing Research Center Division of MaterialsKorea Institute of Science and Technology# 39-1 Haweolgok-DongSungbuk-KuSeoul 136-791Republic of Korea

During the solidification of the AZ91D-alloys, the Al8(Mn, Fe)5 phase is generally precipitated in the melt in advance of the precipitation of the primary α-Mg. The basic principle for manufacturing AZ91D-alloy slurries for semi solid forming is to use the Al8(Mn, Fe)5 precipitates as the heterogeneous nucleation sites for primary α-Mg phases. Microscopic analysis for the location of the Al8(Mn, Fe)5 precipitate explains that the Al8(Mn, Fe)5 precipitate is the effective heterogeneous nucleation site for the primary α-Mg phase. It was also observed that increase of the Mn content in the melt and the cooling rate below to the solid/liquid two-phase region resulted in smaller and more globular primary α-Mg due to the increase of heterogeneous nucleation sites. It was found that the average α-Mg diameter grew as a function of t0.278, where t is the holding time at the solid/liquid two-phase region. This would be attributed to the Ostwald type ripening and coalescence between primary α-Mg phases. The cooling rate below to the solid/liquid two-phase region, Mn content in AZ91D alloy, and the holding time and temperature affected on the quality of slurry.

关键词： AZ91D alloy semi-solid forming solidification heterogeneous nucleation

Motion control design for unmanned ground vehicle in dynamic environment using intelligent controller

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International Journal of Intelligent Computing and Cybernetics 2017年第4期10卷 530-548页

作者： Auday Almayyahi Weiji Wang Alaa Adnan Hussein phil Birch Department of Engineering and Design University of SussexBrightonUK

Purpose–The motion control of unmanned ground vehicles(UGV)is a challenge in the industry of *** purpose of this paper is to propose a fuzzy inference system(FIS)based on sensory information for solving the navigation challenge of UGV in cluttered and dynamic ***/methodology/approach–The representation of the dynamic environment is a key element for the operational field and for the testing of the robotic navigation *** dynamic obstacles move randomly in the operation field,the navigation problem becomes more complicated due to the coordination of the elements for accurate navigation and collision-free path within the environmental *** paper considers the construction of the FIS,which consists of two *** first controller uses three sensors based on the obstacles distances from the front,right and *** second controller employs the angle difference between the heading of the vehicle and the targeted angle to obtain the optimal route based on the environment and reach the desired destination with minimal running power and *** proposed design shows an efficient navigation strategy that overcomes the current navigation challenges in dynamic ***–Experimental analyses are conducted for three different scenarios to investigate the validation and effectiveness of the introduced controllers based on the *** reported simulation results are obtained using MATLAB software *** results show that the controllers of the FIS consistently perform the manoeuvring task and manage the route plan efficiently,even in a complex environment that is populated with dynamic *** paper demonstrates that the destination was reached optimally using the shortest free *** limitations/implications–The paper represents efforts toward building a dynamic environment filled with dynamic obstacles that move at various speeds and *** methodology of designing the FIS is accom

关键词： Fuzzy inference system(FIS) Dynamic obstacles avoidance Intelligent controller Unmanned ground vehicle(UGV)

A framework for dynamic modelling of railway track switches considering the switch blades,actuators and control systems

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Railway Engineering Science 2024年第2期32卷 162-176页

作者： Saikat Dutta Tim Harrison Christopher Ward Roger Dixon phil Winship Institute of Thermofluids School of Mechanical EngineeringUniversity of LeedsLeedsWest YorkshireUK Wolfson School of Mechanical Electrical and Manufacturing EngineeringLoughborough UniversityLoughboroughLeicestershireUK Birmingham Centre for Railway Research and Education School of EngineeringUniversity of BirminghamBirminghamWest MidlandsUK Network Rail Milton KeynesBuckinghamshireUK

The main contribution of this paper is the development and demonstration of a novel methodology that can be followed to develop a simulation twin of a railway track switch system to test the functionality in a digital *** is important because,globally,railway track switches are used to allow trains to change routes;they are a key part of all railway ***,because track switches are single points of failure and safety-critical,their inability to operate correctly can cause significant delays and concomitant *** order to better understand the dynamic behaviour of switches during operation,this paper has developed a full simulation twin of a complete track switch *** approach fuses finite element for the rail bending and motion,with physics-based models of the electromechanical actuator system and the control ***,it provides researchers and engineers the opportunity to explore and understand the design space around the dynamic operation of new switches and switch machines before they are *** is useful for looking at the modification or monitoring of existing switches,and it becomes even more important when new switch concepts are being considered and *** simulation is capable of running in real time or faster meaning designs can be iterated and checked *** paper describes the modelling approach,demonstrates the methodology by developing the system model for a novel“REPOINT”switch system,and evaluates the system level performance against the dynamic performance requirements for the *** the context of that case study,it is found that the proposed new actuation system as designed can meet(and exceed)the system performance requirements,and that the fault tolerance built into the actuation ensures continued operation after a single actuator failure.

关键词： Railway track switch Mathematical modelling Redundant actuation Finite element analysis

Endwall aerodynamic losses from turbine components within gas turbine engines

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Propulsion and Power Research 2017年第1期6卷 1-14页

作者： phil Ligrani Geoffrey Potts Arshia Fatemi Eminent Scholar in Propulsion Professor of Mechanical and Aerospace EngineeringPropulsion Research CenterDepartment of Mechanical and Aerospace EngineeringUniversity of Alabama in Huntsville5000 Technology DriveOlin B.King Technology Hall S236HuntsvilleAlabama 35899USA Aero/Thermal&Heat Transfer Solar TurbinesInc.2200 Pacific HighwayP.O.Box 85376Mail Zone C-9San DiegoCalifornia 92186-5376USA Robert Bosch GmbH(CR/ARF2) Robert Bosch Central Research 130-1Robert Bosch Campus 1Renningen 71272Germany

A survey of research on aerodynamic loss investigations for turbine components of gas tuibine engines is *** and numerically predicted results are presented from investigations undertaken over the past 65 plus *** particular interest are losses from the development of secondary flows from airfoil/endwall *** most important of the airfoilAmdwall secondary flows are passage vortices,counter voitices,and corner *** structure and development of these secondaiy flows are described as they affect aerodynamic perfonnance within and downstream of turbine passage flows in compressible,high speed flows with either subsonic or transonic Mach number distributions,as well as within low-speed,incompressible *** discussed are methods of endwall contouring,and its consequences in regard to airfoil/endwall secondary flows.

关键词： Aerodynamic losses Gas turbine engines Turbine components Airfoil/endwall interactions Secondary flows Vorticity Endwall contouring

Chromothripsis:an emerging crossroad from aberrant mitosis to therapeutic opportunities

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Journal of Molecular Cell Biology 2024年第4期16卷 1-16页

作者： Umer Ejaz Zhen Dou phil YYao Zhikai Wang Xing Liu Xuebiao Yao MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics University of Science and Technology of China School of Life SciencesHefei 230027China Anhui Key Laboratory for Chemical Biology Hefei National Science Center for Inter-disciplinary SciencesHefei 230027China University of California San Diego School of Medicine San DiegoCA 92103USA

Shen Chromothripsis,a type of complex chromosomal rearrangement originally known as chromoanagenesis,has been a subject of extensive investigation due to its potential role in various diseases,particularly *** involves the rapid acquisition of tens to hundreds of structural rearrangements within a short period,leading to complex alterations in one or a few *** phenomenon is triggered by chromosome mis-segregation during *** in accurate chromosome segregation lead to formation of aberrant structural entities such as micronuclei or chromatin *** association between chromothripsis and cancer has attracted significant interest,with potential implications for tumorigenesis and disease *** review aims to explore the intricate mechanisms and consequences of chromothripsis,with a specific focus on its association with mitotic ***,we discuss a comprehensive analysis of crucial molecular entities and pathways,exploring the intricate roles of the CIP2A–TOPBP1 complex,micronuclei formation,chromatin bridge processing,DNA damage repair,and mitotic ***,the review will highlight recent advancements in identifying potential therapeutic targets and the underlying molecular mechanisms associated with chromothripsis,paving the way for future therapeutic interventions in various diseases.

关键词： genomic stability DNA damage repair chromothripsis synthetic lethality cell division

THE EFFECT OF OCCUPANCY ON ELECTRICITY USE IN THREE CANADIAN SCHOOLS

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Journal of Green Building 2018年第1期13卷 95-112页

作者： Mohamed Ouf Mohamed H.Issa phil Merkel Panos Polyzois Department of Civil Engineering University of Manitoba15 Gillson StreetWinnipeg MB R3T 5V6 Canada Customer Engineering Department Manitoba Hydro

Through building performance simulations, previous studies showed the effect of occupants on buildings’ energy consumption. To further demonstrate this effect using empirical evidence, this study analyzed the effect of occupancy on real-time electricity consumption in three case-study schools in Manitoba. Within each school, one classroom as well as the gymnasium were sub-metered to collect real-time electricity consumption data at half-hourly intervals. The study focused on electricity consumption for lighting and plug loads, which make up 30% of energy consumption in Canadian commercial and institutional buildings. A comprehensive method was developed to investigate energy-related occupant behaviour in the sub-metered spaces using four different tools simultaneously: 1) gymnasium bookings after school hours over a four-month period, 2) half-hourly observations of lighting and equipment use in the sub-metered spaces in each school over a two-week period, 3) a daily survey administered to teachers in the sub-metered classrooms over a two-week period, and 4) occupancy and light sensors to evaluate actual recorded occupancy and light use durations over a four-month period. Results showed that recorded occupancy durations over a 4-month period only explained less than 10% of the variations in classrooms’ lighting electricity consumption, meaning that lights may have been used frequently while classrooms were unoccupied. Results also showed the differences in gymnasiums’ electricity consumption were still statistically significant between the three schools, even after school hours and when the gymnasiums were not used or booked for other activities. This study is the first to provide in-depth evaluation of the effect of occupancy on electricity consumption in Canadian schools.

关键词： Occupancy energy efficiency school buildings real-time electricity monitoring