RISS 학술연구정보서비스

검색
다국어 입력

http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.

변환된 중국어를 복사하여 사용하시면 됩니다.

예시)
  • 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
  • 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
닫기
    인기검색어 순위 펼치기

    RISS 인기검색어

      검색결과 좁혀 보기

      선택해제
      • 좁혀본 항목 보기순서

        • 원문유무
        • 원문제공처
        • 등재정보
        • 학술지명
          펼치기
        • 주제분류
        • 발행연도
        • 작성언어

      오늘 본 자료

      • 오늘 본 자료가 없습니다.
      더보기
      • 무료
      • 기관 내 무료
      • 유료
      • KCI등재후보

        Comparison study of the effect of bridge-tunnel transition on train aerodynamic performance with or without crosswind

        Lei Zhou,Tanghong Liu,Zhengwei Chen,Wenhui Li,Zijian Guo,Xuhui He,You-Wu Wang 한국풍공학회 2021 Wind and Structures, An International Journal (WAS Vol.32 No.6

        This paper studied the case of high-speed train running from flat ground to bridges and into/out of tunnels, with or without crosswind based on the Computational Fluid Dynamics (CFD) method. First, the flow structure was analyzed to explain the influence mechanisms of different infrastructures on the aerodynamic characteristics of the train. Then, the evolution of aerodynamic forces of the train during the entire process was analyzed and compared. Additionally, the pressure variation on the train body and the tunnel wall was examined in detail. The results showed that the pressure coefficient and the flow structure on both sides of the high-speed train were symmetrical for no crosswind case. By contrast, under crosswind, there was a tremendous and immediate change in the pressure mapping and flow structure when the train passing through the bridge-tunnel section. The influence of the ground-bridge transition on the aerodynamic forces was much smaller than that of the bridge-tunnel section. Moreover, the variation of aerodynamic load during the process of entering and exiting the bridge-tunnel sections was both significant. In addition, in the case without crosswind, the change in the pressure change in the tunnel conformed to the law of pressure wave propagation, while under crosswind, the variation in pressure was comprehensively affected by both the train and crosswind in the tunnel.

      • KCI등재

        A Novel Resource Scheduling Scheme for CoMP Systems

        ( Wen`an Zhou ),( Jianlong Liu ),( Yiyu Zhang ),( Chengyi Yang ),( Xuhui Yang ) 한국인터넷정보학회 2017 KSII Transactions on Internet and Information Syst Vol.11 No.2

        Coordinated multiple points transmission and reception (CoMP) technology is used to mitigate the inter-cell interference, and increase cell average user normalized throughput and cell edge user normalized throughput. There are two kinds of radio resource schedule strategies in LTE-A/5G CoMP system, and they are called centralized scheduling strategy and distributed scheduling strategy. The regional centralized scheduling cannot solve interference of inter-region, and the distributed scheduling leads to worse efficiency in the utilize of resources. In this paper, a novel distributed scheduling scheme named 9-Cell alternate authorization (9-CAA) is proposed. In our scheme, time-domain resources are divided orthogonally by coloring theory for inter-region cooperation in 9-Cell scenario [6]. Then, we provide a formula based on 0-1 integer programming to get chromatic number in 9-CAA. Moreover, a feasible optimal chromatic number search algorithm named CNS-9CAA is proposed. In addition, this scheme is expanded to 3-Cell scenario, and name it 3-Cell alternate authorization (3-CAA). At last, simulation results indicate that 9/3-CAA scheme exceed All CU CoMP, 9/3C CU CoMP and DLC resource scheduling scheme in cell average user normalized throughput. Especially, compared with the non-CoMP scheme as a benchmark, the 9-CAA and 3-CAA have improved the edge user normalized throughput by 17.2% and 13.0% respectively.

      • KCI등재

        Investigation of Grinding and Lapping Surface Damage Evolution of Fused Silica by Inductively Coupled Plasma Etching

        Zuocai Dai,Shanyong Chen,Xuhui Xie,Lin Zhou 한국정밀공학회 2019 International Journal of Precision Engineering and Vol.20 No.8

        Surface damage has great influence on optical properties, especially the laser-induced damage threshold of optics, and it has become a difficult and basic issue to find suitable methods to efficiently remove the surface damage for improving the surface quality. In this paper, the characteristic evolution of brittle scratch and ground/lapped surface damage during inductively coupled plasma etching (ICPE) process are experimentally investigated on fused silica. Results of damage removal tests show ICPE can efficiently remove brittle scratch and eliminate the lateral and medial cracks. The PV (peak to valley) and RMS (root mean square) values of surface roughness increase with the exposure of lateral and medial cracks, and then gradually decreases with further etching. Finally, the ground and lapped fused silica surfaces with a size of 300 × 300 × 20 mm3 are efficiently processed by ICPE. The power spectral density analysis further demonstrates that the damage can be efficiently removed by ICPE. This study reveals the damage evolution during ICPE process and also provides technical guidance for optimizing the efficient damage removal process to rapidly improve surface quality, precision and fabrication efficiency of fused silica optics.

      • KCI등재후보

        REMOVAL OF CATIONIC DYES FROM AQUEOUS SOLUTION USING CARBON-ENCAPSULATED SUPERPARAMAGNETIC COLLOIDAL NANOPARTICLES AS ADSORBENT

        HUI WANG,QIANWANG CHEN,XUHUI ZHOU 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2013 NANO Vol.8 No.1

        This paper demonstrates the application of negative charge-functionalized carbon-encapsulated superparamagnetic colloidal nanoparticles being as nanoadsorbents for the removal of cationic dyes from aqueous solutions. Adsorption characteristics of the magnetic nanoadsorbents were examined using methylene blue as adsorbates, exhibiting excellent ability to remove cationic dyes from aqueous solutions. In addition, the influences of uptake time, concentration of nanoadsorbents and pH values of aqueous solution on the removal of cationic dyes have been discussed. Results show that the removal efficiency can be up to 90% at a dye concentration of 100 mg L-1 when the uptake time is 1 min, which indicates rapidly removal ability of the magnetic nanoadsorbents. Furthermore, other cationic dyes including rhodamine B and methyl violet were used to examine the universality of nanoadsorbents.

      • Intelligent optimization of axial-flow pump using physics-considering machine learning

        KANKANAM GAMAGE PIYUMIKA MADUSHANI,Zhou Jie,Feng Jiangang,XUHUI ZHOU,Yuan Zheng,Chen Huixiang,Chen Jinbo 한국CDE학회 2024 Journal of computational design and engineering Vol.11 No.1

        To address the significant energy waste generated by axial flow pumps, this paper proposes an intelligent optimization method based on physics-considering machine learning. First, a highly parameterized geometric design theory is constructed using six featured variables to achieve a complete three-dimensional modeling of the blade geometry. Four hundred preliminary cases are studied using the computational fluid dynamics method with various combinations of these featured variables to obtain a preliminary solution. The best preliminary design has an efficiency of 83.33%, and a head of 5.495 m. To further improve this performance, this paper also presents a high-precision prediction model for the energy performance of axial flow pump based on back-propagation neural network and the encoding layers of random sampling and local feature aggregator network created. Afterwards, a multi-population genetic algorithm is used to quickly find the optimal solution within the prediction mode range. The algorithm achieved a highest efficiency of 86.373% and was validated by numerical simulation with a value of 86.057% and a prediction error of 0.316%. Compared with the preliminary solution, the efficiency of the optimized axial flow pump is increased by 1.615%, with a wider high-efficiency range and an optimal operating point closer to the design conditions. Overall, this intelligent optimization method has the potential to significantly reduce the design time of axial pumps and increase their performance.

      연관 검색어 추천

      이 검색어로 많이 본 자료

      활용도 높은 자료

      해외이동버튼