Capacity of Spectrum Sharing Cognitive Radio with MRC Diversity under Delay Quality-of-Service Constraints in Nakagami Fading Environments

( Ping Zhang ),( Ding Xu ),( Zhiyong Feng ) 한국인터넷정보학회 2013 KSII Transactions on Internet and Information Syst Vol.7 No.4

The paper considers a spectrum sharing cognitive radio (CR) network coexisting with a primary network under the average interference power constraint. In particular, the secondary user (SU) is assumed to carry delay-sensitive services and thus shall satisfy a given delay quality-of-service (QoS) constraint. The secondary receiver is also assumed to be equipped with multiple antennas to perform maximal ratio combining (MRC) to enhance SU performance. We investigate the effective capacity of the SU with MRC diversity under aforementioned constraints in Nakagami fading environments. Particularly, we derive the optimal power allocation to achieve the maximum effective capacity of the SU, and further derive the effective capacity in closed-form. In addition, we further obtain the closed-form expressions for the effective capacities under three widely used power and rate adaptive transmission schemes, namely, optimal simultaneous power and rate adaptation (opra), truncated channel inversion with fixed rate (tifr) and channel inversion with fixed rate without truncation (cifr). Numerical results supported by simulations are presented to consolidate our studies. The impacts on the effective capacity of various system parameters such as the number of antennas, the average interference power constraint and the delay QoS constraint are investigated in detail. It is shown that MRC diversity can significantly improve the effective capacity of the SU especially for cifr transmission scheme.

Novel method to prepare polystyrene-based monolithic columns for chromatographic and electrophoretic separations by microwave irradiation

Zhang, Yu-Ping,Ye, Xiong-Wen,Tian, Meng-Kui,Qu, Ling-Bo,Choi, Seong-Ho,Gopalan, Anantha Iyengar,Lee, Kwang-Pill Elsevier 2008 Journal of chromatography A Vol.1188 No.1

<P><B>Abstract</B></P><P>Microwave irradiation can provide a viable alternative to the traditional means such as ultraviolet light and thermal initiation for the preparation of monolithic capillary columns. Polystyrene-based monolithic stationary phases were prepared <I>in situ</I> in fused-silica capillaries and simultaneously in vials. The column permeability, electrophoretic and chromatographic behavior were evaluated using pressure-assisted capillary electrochromatography (pCEC), capillary electrochromatography (CEC) and low pressure liquid chromatography (LPLC). With an optimal monolithic material, the largest theoretical plates for preparing the column could be close to 18,000 plates/m for thiourea in the mode of pCEC. Furthermore, the influence of the composition of the porogenic solvents (toluene/isooctane) on the morphology of organic-based monoliths [poly(styrene-divinylbenzene-methacrylic acid)] was systematically studied with mercury intrusion porosimetry and scanning electron microscopy. The monoliths which were prepared with a high content of isooctane had a bigger pore size and better permeability, and hence resulted in a faster separation.</P>

Phosphino-polycarboxylic acid modified inhibitor nanomaterial for oilfield scale control: Synthesis, characterization and migration

Ping Zhang,Dong Shen,Gedeng Ruan,Amy T. Kan,Mason B. Tomson 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.45 No.-

A facile synthesis approach is reported to prepare scale inhibitor nanomaterial for oilfield scale control. The presence of a polymeric scale inhibitor can considerably change the morphology of the nanomaterialwith a reduced particle size and an enhanced particle stability. In addition, the presence of electrolyte andsonication methods can impact the morphology and stability of the nanomaterial as well. Laboratorytransport experiments suggest that the inhibitor nanomaterial has the future potential for oilfieldmineral scale control. This is thefirst report of the synthesis and characterization of a template-free scaleinhibitor nanomaterial combining both phosphonate and polymeric scale inhibitors.

Line-Interactive UPS for Low-Voltage Microgrids

Ping Zhang,Huanyu Cai,Hengyang Zhao,Jianjiang Shi,Xiangning He 전력전자학회 2015 JOURNAL OF POWER ELECTRONICS Vol.15 No.6

Line-interactive uninterruptible power supply (UPS) systems are good candidates for providing energy storage within a microgrid. In this paper, a control scheme for a line-interactive UPS system applied in a low-voltage microgrid is presented. It is based on the Q-w and P-E droop control to achieve a seamless transition between grid-connected and stand-alone operation modes. Moreover, a new model for designing the controllers is built in the dq-frame based on the instantaneous power definition. The new-built model takes into account the dynamic performance of the output impedance of the inverter in the dq-frame and can be evaluated in the time domain. Compared to the traditional model based on the instantaneous power definition, the new-built model is more accurate to describe the dynamic performance of the system. Simulation and experimental results obtained with a microgrid consisting of two 40-kW line-interactive UPS systems are given to validate the control strategy of the line-active UPS system and the accuracy of the new-built model.

GLOBAL ASYMPTOTIC STABILITY FOR A DIFFUSION LOTKA-VOLTERRA COMPETITION SYSTEM WITH TIME DELAYS

Zhang, Jia-Fang,Zhang, Ping-An Korean Mathematical Society 2012 대한수학회보 Vol.49 No.6

A type of delayed Lotka-Volterra competition reaction-diffusion system is considered. By constructing a new Lyapunov function, we prove that the unique positive steady-state solution is globally asymptotically stable when interspecies competition is weaker than intraspecies competition. Moreover, we show that the stability property does not depend on the diffusion coefficients and time delays.

Possible Epithelial Ovarian Cancer Association with HPV18 or HPV33 Infection

Zhang, Pei-Pei,Zhou, Lei,Cao, Jia-Shi,Li, Yi-Ping,Zeng, Zhi,Sun, Ni,Shen, Li,Zhu, Hao-Yue,Ruan, Yang,Zha, Wen-Ting,Wang, Xin-Yu,Zhang, Ke-Qiang,Zhang, Ran Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.6

The present study was conducted to investigate the prevalence of HPV infection in epithelial ovarian cancer (EOC) in Hunan province. DNA samples were collected from paraffin embedded ovarian tissue from 322 patients with EOC, 99 with ovarian benign tumors and 199 normal persons. The polymerase chain reaction and direct sequencing were used to identify the HPV types in the samples. The relationship between the infection of human papillomavirus (HPV) and the epithelial ovarian carcinoma (EOC) was investigated combined with clinical data. The prevalence of HPV18 and HPV33 in EOC group and benign group was higher than in the normal group. HPV18 and HPV33 may play a role in the development of both EOC and ovarian benign tumor and may participate in the development of EOC with traditional risk factors, family history and abortion, possibly exerting synergistic effects.

Tumor evolution and intratumor heterogeneity of an oropharyngeal squamous cell carcinoma revealed by whole-genome sequencing.

Zhang, Xinyi Cindy,Xu, Chang,Mitchell, Ryan M,Zhang, Bo,Zhao, Derek,Li, Yao,Huang, Xin,Fan, Wenhong,Wang, Hongwei,Lerma, Luisa Angelica,Upton, Melissa P,Hay, Ashley,M?ndez, Eduardo,Zhao, Lue Ping Stockton Press 2013 Neoplasia Vol.15 No.12

<P>Head and neck squamous cell carcinoma (HNSCC) is characterized by significant genomic instability that could lead to clonal diversity. Intratumor clonal heterogeneity has been proposed as a major attribute underlying tumor evolution, progression, and resistance to chemotherapy and radiation. Understanding genetic heterogeneity could lead to treatments specific to resistant and metastatic tumor cells. To characterize the degree of intratumor genetic heterogeneity within a single tumor, we performed whole-genome sequencing on three separate regions of an human papillomavirus (HPV)-positive oropharyngeal squamous cell carcinoma and two separate regions from one corresponding cervical lymph node metastasis. This approach achieved coverage of approximately 97.9% of the genome across all samples. In total, 5701 somatic point mutations (SPMs) and 4347 small somatic insertions and deletions (indels)were detected in at least one sample. Ninety-two percent of SPMs and 77% of indels were validated in a second set of samples adjacent to the discovery set. All five tumor samples shared 41% of SPMs, 57% of the 1805 genes with SPMs, and 34 of 55 cancer genes. The distribution of SPMs allowed phylogenetic reconstruction of this tumor's evolutionary pathway and showed that the metastatic samples arose as a late event. The degree of intratumor heterogeneity showed that a single biopsy may not represent the entire mutational landscape of HNSCC tumors. This approach may be used to further characterize intratumor heterogeneity in more patients, and their sample-to-sample variations could reveal the evolutionary process of cancer cells, facilitate our understanding of tumorigenesis, and enable the development of novel targeted therapies.</P>

Surface-functionalized Hexagonal Mesoporous Silica Supported 5-(4-Carboxyphenyl)-10,15,20-triphenyl Porphyrin Manganese(III) Chloride and Their Catalytic Activity

Zhang, Wei-Jie,Jiang, Ping-Ping,Zhang, Ping-Bo,Zheng, Jia-Wei,Li, Haiyang Korean Chemical Society 2012 Bulletin of the Korean Chemical Society Vol.33 No.12

Manganese(III) 5-(4-carboxyphenyl)-10,15,20-triphenyl porphyrin chloride (Mn(TCPP)Cl) was grafted through amide bond on silica zeolite Y (HY), zeolite beta ($H{\beta}$) and hexagonal mesoporous silica (HMS). XRD, ICP-AES, $N_2$ physisorption, SEM, TEM, FTIR and thermal analysis were employed to analyse these novel heterogeneous materials. These silica supported catalysts were shown to be used for epoxidation and good shape selectivity was observed. The effect of support structure on catalytic performance was also discussed. The catalytic activity remained when the catalysts were recycled five times. The energy changes about epoxidation of alkenes by $NaIO_4$ and $H_2O_2$ were also computationally calculated to explain the different catalytic efficiency.

Inhibition of c-FLIP by RNAi Enhances Sensitivity of the Human Osteogenic Sarcoma Cell Line U2OS to TRAILInduced Apoptosis

Zhang, Ya-Ping,Kong, Qing-Hong,Huang, Ying,Wang, Guan-Lin,Chang, Kwen-Jen Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.6

To study effects of cellular FLICE (FADD-like IL-$1{\beta}$-converting enzyme)-inhibitory protein (c-FLIP) inhibition by RNA interference (RNAi) on sensitivity of U2OS cells to tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL)-induced apoptosis, plasmid pSUPER-c-FLIP-siRNA was constructed and then transfected into U2OS cells. A stable transfection cell clone U2OS/pSUPER-c-FLIP-siRNA was screened from the c-FLIP-siRNA transfected cells. RT-PCR and Western blotting were applied to measure the expression of c-FLIP at the levels of mRNA and protein. The results indicated that the expression of c-FLIP was significantly suppressed by the c-FLIP-siRNA in the cloned U2OS/pSUPER-c-FLIP-siRNA as compared with the control cells of U2OS/pSUPER. The cloned cell line of U2OS/pSUPER-c-FLIP-siRNA was further examined for TRAILinduced cell death and apoptosis in the presence of a pan-antagonist of inhibitor of apoptosis proteins (IAPs) AT406, with or without 4 hrs pretreatment with rocaglamide, an inhibitor of c-FLIP biosynthesis, for 24 hrs. Cell death effects and apoptosis were measured by the methods of MTT assay with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and flow cytometry, respectively. The results indicated that TRAIL-induced cell death in U2OS/pSUPER-c-FLIP-siRNA was increased compared with control cells U2OS/pSUPER in the presence or absence of AT406. Flow cytometry indicated that TRAIL-induced cell death effects proceeded through cell apoptosis pathway. However, in the presence of rocaglamide, cell death or apoptotic effects of TRAIL were similar and profound in both cell lines, suggesting that the mechanism of action for both c-FLIP-siRNA and rocaglamide was identical. We conclude that the inhibition of c-FLIP by either c-FLIP-siRNA or rocaglamide can enhance the sensitivity of U2OS to TRAIL-induced apopotosis, suggesting that inhibition of c-FLIP is a good target for anti-cancer therapy.

Performance bounds for relative configuration and global transformation in cooperative localization

Ping Zhang,Jian Lu,Qiao Wang 한국통신학회 2016 ICT Express Vol.2 No.1

Cooperative localization introduces internode measurements to provide the node relative locations instead of absolute locations. This paper decomposes the absolute locations into relative configuration and global transformation, where the former can be specified by the internode measurements while the latter requires reference information. This decomposition can be used to investigate the relative localization which uses only internode measurements and the absolute localization with the consideration of anchor location uncertainty. After deriving the coordinate representations, error metric, and performance bounds for the global transformation, we evaluate the performance of a node location calibration that uses the measurements from sources in unknown locations.