An Analytical Solution for Voltage Stability Studies Incorporating Wind Power

Lin, Yu-Zhang,Shi, Li-Bao,Yao, Liang-Zhong,Ni, Yi-Xin,Qin, Shi-Yao,Wang, Rui-Ming,Zhang, Jin-Ping The Korean Institute of Electrical Engineers 2015 Journal of Electrical Engineering & Technology Vol.10 No.3

Voltage stability is one of the most critical security issues which has not yet been well resolved to date. In this paper, an analytical method called PQ plane analysis with consideration of the reactive power capability of wind turbine generator and the wake effect of wind farm is proposed for voltage stability study. Two voltage stability indices based on the proposed PQ plane analysis method incorporating the uncertainties of load-increasing direction and wind generation are designed and implemented. Cases studies are conducted to investigate the impacts of wind power incorporation with different control modes. Simulation results demonstrate that the constant voltage control based on reactive power capability significantly enhances voltage stability in comparison of the conventional constant power factor control. Some meaningful conclusions are obtained.

Risk Factors for Cervical Cancer in Rural Areas of Wuhan China: a Matched Case-control Study

Zhang, Bin,Zhou, Ai-Fen,Zhu, Chang-Cai,Zhang, Ling,Xiang, Bing,Chen, Zhong,Hu, Rong-Hua,Zhang, Ya-Qi,Qiu, Lin,Zhang, Yi-Ming,Xiong, Chao-Du,Du, Yu-Kai,Shi, Yu-Qin Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.12

Cervical cancer is a serious public health problem in developing countries. We investigated possible risk factors for cervical cancer in rural areas of Wuhan China using a matched case-control study with 33 women diagnosed with cervical cancer and 132 healthy women selected from the same area as matched controls. A questionnaire, which included questions about general demography conditions, environmental and genetic factors, the first sexual intercourse, first marriage age, age at first pregnancy, pregnancy first child's age, female personal health history, social psychological factors, dietary habits, smoking and alcohol status and other living habits was presented to all participants. At the same time, HPV infection of every participant was examined in laboratory testing. Results showed HPV infection (P<0.000, OR=23.4) and pregnancy first child's age (P<0.000, OR=13.1) to be risk factors for cervical cancer. Menopause (P=0.003, OR=0.073) was a protective factor against cervical cancer. However, there was no indication of associations of environmental (drinking water, insecticide, disinfectant) genetic (cancer family history), or life-style factors (smoking status, alcohol status, physical training, sleep quality), including dietary habits (intake of fruit and vegetable, meat, fried food, bean products and pickled food) or social psychological factors with cervical cancer. The results suggest that the risk of cervical cancer in Chinese rural women may be associated with HPV infection, menopause and the pregnancy first child's age.

rs10505474 and rs7837328 at 8q24 Cumulatively Confer Risk of Prostate Cancer in Northern Han Chinese

Zhang, Lin-Lin,Sun, Liang,Zhu, Xiao-Quan,Xu, Yong,Yang, Kuo,Yang, Fan,Yang, Yi-Ge,Chen, Guo-Qiang,Fu, Ji-Cheng,Zheng, Chen-Guang,Li, Ying,Mu, Xiao-Qiu,Shi, Xiao-Hong,Zhao, Fan,Wang, Fei,Yang, Ze,Wang, Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.7

Aims: Genome-wide association studies (GWAS) have identified several risk variants for prostate cancer (pCa) mainly in Europeans, which need to be further verified in other racial groups. We selected six previously identified variants as candidates and to define the association with PCa in Northern Han Chinese. Methods: 749 subjects from Beijing and Tianjin in Northern China were included. Six variants (rs10505474, rs7837328, rs4242384, rs7813, rs486907 and rs1058205) were genotyped by high resolution melting (HRM) assays. The individual and cumulative contribution for of the risk of PCa and clinical covariates were analyzed. Results: Among the six candidate variants, onlyrs10505474, and rs7837328, both locating at 8q24 region, were associated with PCa in our population.rs10505474 (A) was associated with PCa ($OR_{recessive}=1.56$, p=0.006); and rs7837328 (A) was associated with PCa ($OR_{dominant}=1.38$, p=0.042/$OR_{recessive}=1.99$, p=0.003). Moreover, we observed a cumulative effects between them ($p_{trend}=2.58{\times}10^{-5}$). The joint population attributable risk showed the two variants might account for 71.85% of PCa risk. In addition, we found the homozygotes of rs10505474 (A) and rs7837328 (A) were associated with PCa clinical covariants (age at onset, tumor stage, respectively) ($p_{age}=0.046$, $P_{tumorstage}=0.048$). Conclusion: rs10505474 (A) and rs7387328 (A) at 8q24 are associated with PCa and cumulatively confer risk, suggesting the two variations could determine susceptibility to PCa in the Northern Chinese Han population.

CNOP-Based Sensitive Areas Identification for Tropical Cyclone Adaptive Observations with PCAGA Method

Lin-Lin Zhang,Shi-Jin Yuan,Bin Mu,Fei-Fan Zhou 한국기상학회 2017 Asia-Pacific Journal of Atmospheric Sciences Vol.53 No.1

In this paper, conditional nonlinear optimal perturbation (CNOP) was investigated to identify sensitive areas for tropical cyclone adaptive observations with principal component analysis based genetic algorithm (PCAGA) method and two tropical cyclones, Fitow (2013) and Matmo (2014), were studied with a 120 km resolution using the fifth-generation Mesoscale Model (MM5). To verify the effectiveness of PCAGA method, CNOPs were also calculated by an adjoint-based method as a benchmark for comparison on patterns, energies, and vertical distributions of temperatures. Comparing with the benchmark, the CNOPs obtained from PCAGA had similar patterns for Fitow and a little different for Matmo; the vertically integrated energies were located closer to the verification areas and the initial tropical cyclones. Experimental results also presented that the CNOPs of PCAGA had a more positive impact on the forecast improvement, which gained from the reductions of the CNOPs in the whole domain containing sensitive areas. Furthermore, the PCAGA program was executed 40 times for each case and all the averages of benefits were larger than the benchmark. This also proved the validity and stability of the PCAGA method. All results showed that the PCAGA method could approximately solve CNOP of complicated models without computing adjoint models, and obtain more benefits of reducing the CNOPs in the whole domain.

Digital Image-based Identification Method for the Determination of the Particle Size Distribution of Dam Granular Material

Shi-lin Zhang,Gao-jian Wu,Xingguo Yang,Wan-hong Jiang,Jia-wen Zhou 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.8

The Particle Size Distribution (PSD) properties of dam granular material plays an important role in the construction process ofearth-rock dams, as it can affect the filling quality and structural safety. However, the conventional sieving method employed tocheck the PSD is labor-intensive, time-consuming and not highly accurate. In this study, a digital image-based identification methodis presented for the determination of the PSD of dam granular material, which mainly incorporates image acquisition technology, alarge database and a neural network. Digital Image Processing (DIP) technology is used to recognize the geometric size and gradingcurve of dam granular materials at a small scale, while statistical distribution models are used to determine the characteristicparameters of the grading curve and convert the graphical curve into mathematical variables. Furthermore, a large database and a BPneutral algorithm, which is improved using a genetic algorithm, are introduced as tools to reveal the implicit relationship between theDIP and sieving grading curves to correct the error of identification. A case study for the Changheba Hydropower Station is used toillustrate the implementation details of the presented method. The identification results demonstrate that the presented method canacquire and assess the gradation in spite of a degree of error, which can be decreased when more advanced DIP technologies areexplored, the amount of data in the database is increased, and a more optimized network algorithm is adopted.

An Analytical Solution for Voltage Stability Studies Incorporating Wind Power

Yu-Zhang Lin,Li-Bao Shi,Liang-Zhong Yao,Yi-Xin Ni,Shi-Yao Qin,Rui-Ming Wang,Jin-Ping Zhang 대한전기학회 2015 Journal of Electrical Engineering & Technology Vol.10 No.3

Voltage stability is one of the most critical security issues which has not yet been well resolved to date. In this paper, an analytical method called PQ plane analysis with consideration of the reactive power capability of wind turbine generator and the wake effect of wind farm is proposed for voltage stability study. Two voltage stability indices based on the proposed PQ plane analysis method incorporating the uncertainties of load-increasing direction and wind generation are designed and implemented. Cases studies are conducted to investigate the impacts of wind power incorporation with different control modes. Simulation results demonstrate that the constant voltage control based on reactive power capability significantly enhances voltage stability in comparison of the conventional constant power factor control. Some meaningful conclusions are obtained.

Inhibition of Transient Receptor Potential Melastain 7 Enhances Apoptosis Induced by TRAIL in PC-3 cells

Lin, Chang-Ming,Ma, Ji-Min,Zhang, Li,Hao, Zong-Yao,Zhou, Jun,Zhou, Zhen-Yu,Shi, Hao-Qiang,Zhang, Yi-Fei,Shao, En-Ming,Liang, Chao-Zhao Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.10

Transient receptor potential melastain 7 (TRPM7) is a bifunctional protein with dual structure of both ion channel and protein kinase, participating in a wide variety of diseases including cancer. Recent researches have reported the mechanism of TRPM7 in human cancers. However, the correlation between TRPM7 and prostate cancer (PCa) has not been well studied. The objective of this study was to investigate the potential the role of TRPM7 in the apoptosis of PC-3 cells, which is the key cell of advanced metastatic PCa. In this study, we demonstrated the influence and potential function of TRPM7 on the PC-3 cells apoptosis induced by TNF-related apoptosis inducing-ligand (TRAIL). The study also found a novel up-regulated expression of TRPM7 in PC-3 cells after treating with TRAIL. Suppression of TRPM7 by TRPM7 non-specific inhibitors ($Gd^{3+}$ or 2-aminoethoxy diphenylborate (2-APB) ) not only markedly eliminated TRPM7 expression level, but also increased the apoptosis of TRAIL-treated PC-3 cells, which may be regulated by the phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) signaling pathway accompany with up-regulated expression of cleaved Caspase-3, (TRAIL-receptor 1, death receptors 4) DR4, and (TRAIL-receptor 2, death receptors 5) DR5. Taken together, our findings strongly suggested that TRPM7 was involved in the apoptosis of PC-3 cells induced by TRAIL, indicating that TRPM7 may be applied as a therapeutic target for PCa.

Effects of stiffening rings on the dynamic properties of hyperboloidal cooling towers

Zhang, Jun-Feng,Chen, Huai,Ge, Yao-Jun,Zhao, Lin,Ke, Shi-Tang Techno-Press 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.49 No.5

As hyperboloidal cooling towers (HCTs) growing larger and slender, they become more sensitive to gust wind. To improve the dynamic properties of HCTs and to improve the wind resistance capability, stiffening rings have been studied and applied. Although there have been some findings, the influence mechanism of stiffening rings on the dynamic properties is still not fully understood. Based on some fundamental perceptions on the dynamic properties of HCTs and free ring structures, a concept named "participation degree" of stiffening rings was proposed and the influence mechanism on the dynamic properties was illustrated. The "participation degree" is determined by the modal deform amplitude and latitude wave number of stiffening rings. Larger modal deform amplitude and more latitude waves can both result in higher participation degree and more improvement to eigenfrequencies. Also, this concept can explain and associate the pre-existing independent findings.

Bipolar resistive switching characteristics of atomic layer deposited Nb_2O_5 thin films for nonvolatile memory application

Lin Chen,Qing-Qing Sun,Jing-Jing Gu,Yan Xu,Shi-Jin Ding,David Wei Zhang 한국물리학회 2011 Current Applied Physics Vol.11 No.3

Resistive switching behavior of Nb_2O_5 prepared by atomic layer deposition was investigated as a promising candidate for next generation nonvolatile memory technology. The crystalline structure of deposited film at 300 ℃ was found to be polycrystalline by X-ray diffraction (XRD) and the film was estimated to be oxygen deficient by X-ray photoelectron spectroscopy (XPS). The low resistance ON state and high resistance OFF state can be reversibly altered under low voltage about ±1 V. More than 1000reproducible switching cycles by DC voltage sweep were observed with a resistance ratio above 10,which was large enough to read out for memory applications. Moreover, the HRS and LRS of the devices are stable for more than 5 × 10^4 s and does not show any degradation during the test.

Predictive Potential of Glutathione S-Transferase Polymorphisms for Prognosis of Osteosarcoma Patients on Chemotherapy

Zhang, Shai-Lin,Mao, Ning-Fang,Sun, Jun-Ying,Shi, Zhi-Cai,Wang, Bing,Sun, Yong-Jian Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.6

Objective: To evaluate the predictive value of glutathione S-transferase (GST) gene polymorphisms for the prognosis of osteosarcoma patients receiving chemotherapy. Methods: A total of 159 patients were included in our study between January 2005 and December 2007., with follow-up until January 2012. Genotyping was based upon the duplex polymerase-chain-reaction with the PCR-CTPP method. Results: At the time of diagnosis, 15.4% of the patients presented with metastasis, while 22.3% developed metastasis during follow-up. At the time of final analysis on January 2012, the median follow-up was 45.5 months. Patients with null GSTM1 and GSTT1 had a higher event free survival rate than non-null genotype, but no significant association was found between the two genotypes and prognosis of osteosarcoma. Individuals with GSTP1 Val/Val genotype tended to live shorter than with the IIe/IIe genotype, and we found a significantly higher risk of death from osteosarcoma (adjusted HR=2.35, 95% CI=1.13-4.85). Conclusion: The GSTP1 gene polymorphism may have an important role in the prognosis of osteosarcoma patients with chemotherapy. Further analyses with larger samples and more genes encoding metabolizing and DNA repair enzymes are warranted.