• Title/Summary/Keyword: Qun

검색결과 164건 처리시간 0.029초

Reducing the Interference in Compact MIMO Antennas of CRLH-TL-Based Broadside-Capacitive and Slot Couplings

  • Jang, Kyeongnam;Kahng, Sungtek;Yang, Inkyu;Kim, Hyeongseok;Wu, Qun
    • Journal of Electrical Engineering and Technology
    • /
    • 제9권3호
    • /
    • pp.997-1001
    • /
    • 2014
  • In this paper, the interference in small MIMO antennas having two identical composite right- and left-handed transmission-line(CRLH-TL)-based radiating elements is remarkably decreased. The radiating element has the broadside-capacitive coupling as well as slots to be equivalent to the CRLH-TL to prevent the size from increasing for an LTE high band. The suspended line bridging the two radiating elements is optimized to lower the interference between them down to -23 dB, while the overall MIMO antenna system is compact and its antenna performance is acceptable. The design is tested for 2.5 GHz.

Potent in Vitro Anticancer Activity of Metacycloprodigiosin and Undecylprodigiosin from a Sponge-Derived Actinomycete Saccharopolyspora sp. nov.

  • Liu, Rui;Cui, Cheng-Bin;Duan, Lin;Gu, Qian-Qun;Zhu, Wei-Ming
    • Archives of Pharmacal Research
    • /
    • 제28권12호
    • /
    • pp.1341-1344
    • /
    • 2005
  • Bioassay-guided fractionation of $CHCl_{3}$ extract from the fermentation broth of a sponge Mycale plumose-derived actinomycete Saccharopolyspora sp. nov., led to the isolation of two known prodigiosin analogs - metacycloprodigiosin (1) and undecylprodigiosin (2). These compounds exhibited significant cytotoxic activities against five cancer cell lines: P388, HL60, A-549, BEL­7402, and SPCA4. This is the first report on the significant cytotoxicity of metacycloprodigiosin (1) against human cancer cell lines.

혈관 통과 시간을 활용한 고정확도 제 1심음 및 제 2심음 자동식별 알고리즘 개발 (Development of High-Accuracy Automatic Identification Algorithm for First and Second Heart Sounds Using Vascular Transit Time)

  • 이수민;웨이췬;박희준
    • 한국멀티미디어학회논문지
    • /
    • 제24권11호
    • /
    • pp.1500-1507
    • /
    • 2021
  • Identification and analysis of the first and second heart sounds(S1, S2) is the easiest way for cardiovascular disease prevention and early diagnosis. However, accurate identification is difficult because the heart sound includes organ movement, blood vortex, user experience, and noise influenced by subjective judgment. Therefore, an algorithm to automatically identify the S1 and S2 heart sounds based on blood vessel transit time(VTT) is presented in this paper. According to the experimental results of comparing the algorithm developed for S1 and S2 heart sound analysis with the conventional Shannon energy algorithm in 10 volunteers, it has been proven that the proposed algorithm can automatically identify S1 and S2 heart sounds with higher accuracy than existing algorithms.

A cohesive model for concrete mesostructure considering friction effect between cracks

  • Huang, Yi-qun;Hu, Shao-wei
    • Computers and Concrete
    • /
    • 제24권1호
    • /
    • pp.51-61
    • /
    • 2019
  • Compressive ability is one of the most important mechanical properties of concrete material. The compressive failure process of concrete is pretty complex with internal tension, shear damage and friction between cracks. To simulate the complex fracture process of concrete at meso level, methodology for meso-structural analysis of concrete specimens is developed; the zero thickness cohesive elements are pre-inserted to simulate the crack initiation and propagation; the constitutive applied in cohesive element is established to describe the mechanism of crack separation, closure and friction behavior between the fracture surfaces. A series of simulations were carried out based on the model proposed in this paper. The results reproduced the main fracture and mechanical feature of concrete under compression condition. The effect of key material parameters, structure size, and aggregate content on the concrete fracture pattern and loading carrying capacities was investigated. It is found that the inner friction coefficient has a significant influence on the compression character of concrete, the compression strength raises linearly with the increase of the inner friction coefficient, and the fracture pattern is sensitive to the mesostructure of concrete.

A fast gamma-ray dose rate assessment method for complex geometries based on stylized model reconstruction

  • Yang, Li-qun;Liu, Yong-kuo;Peng, Min-jun;Li, Meng-kun;Chao, Nan
    • Nuclear Engineering and Technology
    • /
    • 제51권5호
    • /
    • pp.1436-1443
    • /
    • 2019
  • A fast gamma-ray dose rate assessment method for complex geometries based on stylized model reconstruction and point-kernel method is proposed in this paper. The complex three-dimensional (3D) geometries are imported as a 3DS format file from 3dsMax software with material and radiometric attributes. Based on 3D stylized model reconstruction of solid mesh, the 3D-geometrical solids are automatically converted into stylized models. In point-kernel calculation, the stylized source models are divided into point kernels and the mean free paths (mfp) are calculated by the intersections between shield stylized models and tracing ray. Compared with MCNP, the proposed method can implement complex 3D geometries visually, and the dose rate calculation is accurate and fast.

Prognostic Significance of C-reactive Protein in Urological Cancers: a Systematic Review and Meta-analysis

  • Dai, Jin;Tang, Kun;Xiao, Wei;Yu, Gan;Zeng, Jin;Li, Wei;Zhang, Ya-Qun;Xu, Hua;Chen, Zhi-Qiang;Ye, Zhang-Qun
    • Asian Pacific Journal of Cancer Prevention
    • /
    • 제15권8호
    • /
    • pp.3369-3375
    • /
    • 2014
  • Background: C-reactive protein (CRP), considered as a prototypical inflammatory cytokine, has been proposed to be involved in tumor progression through inflammation. Recent studies have indicated CRP as a progostic predictor for urological cancers, but the results remain controversial. Materials and Methods: A systematic search of Medline, Scopus and the Cochrane Library was performed to identify eligible studies published between Jan 1, 2001 and Sep 1, 2013. Outcomes of interest were collected from studies comparing overall survival (OS), cancer-specific survival (CSS) and relapse-free survival (RFS) in patients with elevated CRP levels and those having lower levels. Studies were pooled, and combined hazard ratio (HR) of CRP with its 95% confidence interval (CI) for survival were used for the effect size estimate. Results: A total of 43 studies (7,490 patients) were included in this meta-analysis (25 for RCC, 10 for UC, and 8 for PC). Our pooled results showed that elevated serum CRP level was associated with poor OS (HR: 1.26, 95%CI: 1.22-1.30) and RFS (HR: 1.38 95%CI: 1.29-1.47), respectively. For CSS the pooled HR (HR: 1.33, 95%CI: 1.28-1.39) for higher CRP expression could strongly predict poorer survival in urological cancers. Simultaneously, elevated serum CRP was also significantly associated with poor prognosis in the subgroup analysis. Conclusions: Our pooled results demonstrate that a high serum level of CRP as an inflammation biomarker denotes a poor prognosis of patients with urological cancers. Further large prospective studies should be performed to confirm whether CRP, as a biomarker of inflammation, has a prognostic role in urological cancer progression.

A Design of Mid-wave Infrared Integral Catadioptric Optical System with Wide FOV

  • Yu, Lin Yao;Jia, Hong Guang;Wei, Qun;Jiang, Hu Hai;Zhang, Tian Yi;Wang, Chao
    • Journal of the Optical Society of Korea
    • /
    • 제17권2호
    • /
    • pp.142-147
    • /
    • 2013
  • In order to deduce the difficulty of fixing the Ritchey-Chretien (R-C) dual reflective optical system and enhance the stability of the secondary mirror, a compact integral structure is presented here composed of two transmitting and two reflective aspheric surfaces. The four surfaces were manufactured from a single germanium lens and integrated together. The two reflective surfaces formed by coating the inner reflecting films were assembled in one lens. It makes the installation of the two mirrors easier and the structure of the secondary mirror more stable. A design of mid-wave infrared (MWIR) compact imaging system is presented with a spectral range chosen as $3.7-4.8{\mu}m$. The effective focal length is f=90 mm. The field of view (FOV) for the lens is $4.88^{\circ}$. It has good imaging capability with Modulation Transfer Function (MTF) of all field of view more than 0.55 close to the diffraction limitation. Outdoor experiments were carried out and it is shown that the integral catadioptric optical system performs well on imaging.

Power Quality Warning of High-Speed Rail Based on Multi-Features Similarity

  • Bai, Jingjing;Gu, Wei;Yuan, Xiaodong;Li, Qun;Chen, Bing;Wang, Xuchong
    • Journal of Electrical Engineering and Technology
    • /
    • 제10권1호
    • /
    • pp.92-101
    • /
    • 2015
  • As one type of power quality (PQ) disturbance sources, high-speed rail (HSR) can have major impacts on the power supply grid. Providing timely and accurate warning information for PQ problems of HSR is important for the safe and stable operation of traction power supply systems and the power supply grid. This study proposes a novel warning approach to identify PQ problems and provide warning prompts based on the monitored data of HSR. To embody the displacement and status change of monitored data, multi-features of different sliding windows are computed. To reflect the relative importance degree of these features in the overall evaluation, an analytic hierarchy process (AHP) is used to analyse the weights of multi-features. Finally, a multi-features similarity algorithm is applied to analyse the difference between monitored data and the reference data of HSR, and PQ warning results based on dynamic thresholds can be analysed to quantify its severity. Cases studies demonstrate that the proposed approach is effective and feasible, and it has now been applied to an actual PQ monitoring platform.

Effects of traffic characteristics on pavement responses at the road intersection

  • Yang, Qun;Dai, Jingwang
    • Structural Engineering and Mechanics
    • /
    • 제47권4호
    • /
    • pp.531-544
    • /
    • 2013
  • Compared with pavement structures of ordinary road sections, pavement structures in the intersection are exposed to more complex traffic characteristics which may exacerbates pavement distresses such as fatigue-cracking, shoving, shear deformation and rutting. Based on a field survey about traffic characteristics in the intersection conducted in Shanghai China, a three dimensional dynamic finite-element model was developed for evaluating the mechanistic responses in the pavement structures under different traffic characteristics, namely uniform speed, acceleration and deceleration. The results from this study indicated that : (1) traffic characteristics have significant effects on the distributions of the maximum principal strain (MPS) and the maximum shear stress (MSS) at the pavement surface; (2) vehicle acceleration or deceleration substantially impact the MPS and MSS at pavement surface and could increase the magnitude of them by 20 percent to 260 percent; (3) in the vertical direction, with the increase of vehicle deceleration rate, the location of the MPS peak value and the MSS peak value changes from the sub-surface layer to the pavement surface.

Compact Dual-Band Three-Way Metamaterial Power-Divider with a Hybrid CRLH Phase-Shift Line

  • Jang, Kyeongnam;Kahng, Sungtek;Jeon, Jinsu;Wu, Qun
    • Journal of electromagnetic engineering and science
    • /
    • 제14권1호
    • /
    • pp.15-24
    • /
    • 2014
  • A compact dual-band three-way metamaterial power divider is proposed that has three in-phase outputs. Fully printed composite rightand left-handed (CRLH) unequal and equal power dividers are first implemented for 900-MHz and 2.4-GHz bands with the power-division ratios of 2:1 and 1:1, respectively. An initial 1:1:1 power divider is then achieved by incorporating the input of the two-way equal block into an output of the unequal block, and trimming the interconnection parameters. The condition of an identical phase at the three outputs of the power divider is then met by devising a hybrid CRLH phase-shift line to compensate for the different phase errors at the two frequencies. This scheme is confirmed by predicting the performance of the power divider with circuit analysis and full-wave simulation and measuring the fabricated prototype. They results show agreement; the in-phase outputs as well as the desirable power-division are accomplished and outdo the conventional techniques.