Control of Cascaded H-Bridges STATCOM based on the Power Flow Management

Ping-Heng Wu,Chia-Tse Lee,Hsin-Chin Chen,Po-Tai Cheng 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

As smart grid techniques are getting more positive perspective and expected to grow in the future, the STATic synchronous COMpensator (STATCOM) has become one of the most important roles to manage the power flow and regulate the grid voltage. The Modular Multilevel Cascaded Converter (MMCC) based on single star bridge cell (SSBC) is very suitable for STATCOM application at the medium-voltage level in the power system. The dc capacitors voltage balancing control is a critical issue to secure the stable operation of MMCCSSBC converter. Four different control methods based on power flow analysis have been considered. The performance of each controller is evaluated under steady state or even Low Voltage Ride Through (LVRT) operation. Each controller has its power flow management and its feature. Experimental test results are given to verify these control methods can well regulated the dc bus voltages under the unbalanced grid voltages.

Harmine Induces Apoptosis of HepG2 Cell via Mitochondrial Signaling Pathway

( Heng Yu ),( Yan Ping Zhang ) 조선대학교 공학기술연구원 2011 공학기술논문지 Vol.4 No.3

Harmine exhibited a strong inhibitory effect on the grow고 and proliferation of HepG2 cell line in a dose dependent manner. Hoechest 33258 staining revealed that the nuclear fragmentation, chromosomal cells, condensed shrank and were appeared in the HepG2 treated with Harmine. The percentage of the sub/G1 fraction was increased in a concentration dependent manner, indicating that the apoptotic cell death. PI staining experiment showed that Harmine was HepG2 cell change the cell cycle distribution of HepG2, cell and decreased the proportion of cells in G0-G1 phase. Although, increased the proportion of S phase cells and G2-M phase cells. Harmine induced apoptosis in HepG2 cells in a concentration dependent manner, with occurrence rates of apoptotic cells of 20.00%, 32.70% and 64.90%, respectively. JC-1 showed a decrease in mitochondrial membrane potential. Apoptosis of HepG2 cells was associated with Caspase-3 and Caspase-9 activation. down-regulation of Bcl-2, Mcl-1, Bcl-x1 and n -change of Bax. It seems that Harmine exhibited an anti-proliferative effect in HepG2 cells via mitochondrial signal pathways. The cancer-specific selectivity have shown in this study. suggested that Harmine could be a promising novel drug for human hepatocellular carcinoma.

Assistive Control of a Surgical Robot Based on Bilateral Interacted Force Analysis

Ping-Lang Yen,Shang-Wei Hsu,Hang-Ting Lin,Ching-Heng Wang 제어로봇시스템학회 2012 제어로봇시스템학회 국제학술대회 논문집 Vol.2012 No.10

Interacted force between a robot, human and anatomical object in orthopedic surgery provides crucial information for safe and accurate bone cutting. When the robot plays the role of assisting the surgeon in the whole surgical procedure, the robot is trying to comply with the human intention according to various cutting conditions. The reaction force to the robot from the human is for indicating human intention, whereas the force from the anatomical object reflects the cutting condition. In this paper two impedance indices are defined by these two interacted forces and a surgical robot then decides whether assistive or resistant action is activated so that accuracy and safety of bone cutting can be achieved.

Poster Presentations : Basic Research, Parenteral Nutrition ; Complications Occurring During Total Parenteral Nutrition

( Heng Sim Lee ),( Chung Ping Hsu ),( Yu Ling Changen ),( Ben Yuan Chan ) 한국정맥경장영양학회 2005 The 11th PENSA Congress Vol.2005 No.-

Parsing the Security of Bluetooth

Zhen-Ping Lan,Xue-Heng Tao,Xin Zhao 한국멀티미디어학회 2006 한국멀티미디어학회 국제학술대회 Vol.2006 No.-

Bluetooth is very susceptible to attacks for using radio waves to transfer information. This paper is just concerned with the security of Bluetooth system. The safe tasks and system structure of Bluetooth technology are discussed first of all. On the basis of that, the mechanism of authentication and encryption is investigated mainly. In the end, it constructively puts forward some feasible solve measures aiming at these existing flaws and possible security holes.

Temporal and spatial impact of Spartina alterniflora invasion on methanogens community in Chongming Island, China

Xue Ping Chen,Jing Sun,Yi Wang,Heng Yang Zhang,Chi Quan He,Xiao Yan Liu,Nai Shun Bu,Xi-En Long 한국미생물학회 2018 The journal of microbiology Vol.56 No.7

Methane production by methanogens in wetland is recognized as a significant contributor to global warming. Spartina alterniflora (S. alterniflora), which is an invasion plant in China’s wetland, was reported to have enormous effects on methane production. But studies on shifts in the methanogen community in response to S. alterniflora invasion at temporal and spatial scales in the initial invasion years are rare. Sediments derived from the invasive species S. alterniflora and the native species Phragmites australis (P. australis) in pairwise sites and an invasion chronosequence patch (4 years) were analyzed to investigate the abundance and community structure of methanogens using quantitative real-time PCR (qPCR) and Denaturing gradient gel electrophoresis (DGGE) cloning of the methyl-coenzyme M reductase A (mcrA) gene. For the pairwise sites, the abundance of methanogens in S. alterniflora soils was lower than that of P. australis soils. For the chronosequence patch, the abundance and diversity of methanogens was highest in the soil subjected to two years invasion, in which we detected some rare groups including Methanocellales and Methanococcales. These results indicated a priming effect at the initial invasion stages of S. alterniflora for microorganisms in the soil, which was also supported by the diverse root exudates. The shifts of methanogen communities after S. alterniflora invasion were due to changes in pH, salinity and sulfate. The results indicate that root exudates from S. alterniflora have a priming effect on methanogens in the initial years after invasion, and the predominate methylotrophic groups (Methanosarcinales) may adapt to the availability of diverse substrates and reflects the potential for high methane production after invasion by S. alterniflora.

Estimation of the Number of Sources Based on Hypothesis Testing

Manlin Xiao,Ping Wei,Heng-Ming Tai 한국통신학회 2012 Journal of communications and networks Vol.14 No.5

Accurate and efficient estimation of the number of sources is critical for providing the parameter of targets in problems of array signal processing and blind source separation among other such problems. When conventional estimators work in unfavorable scenarios, e.g., at low signal-to-noise ratio (SNR), with a small number of snapshots, or for sources with a different strength,it is challenging to maintain good performance. In this paper, the detection limit of theminimumdescription length (MDL) estimator and the signal strength required for reliable detection are first discussed. Though a comparison, we analyze the reason that performances of classical estimators deteriorate completely in unfavorable scenarios. After discussing the limiting distribution of eigenvalues of the sample covariance matrix, we propose a new approach for estimating the number of sources which is based on a sequential hypothesis test. The new estimator performs better in unfavorable scenarios and is consistent in the traditional asymptotic sense. Finally,numerical evaluations indicate that the proposed estimator performs well when compared with other traditional estimators at low SNR and in the finite sample size case, especially when weak signals are superimposed on the strong signals.

中韓社會保障制度比較硏究

( Gui Zhen Heng ),( Fan Ping ) 한국행정학회 2010 한국행정학회 학술발표논문집 Vol.2010 No.-

Estimation of the Number of Sources Based on Hypothesis Testing

Xiao, Manlin,Wei, Ping,Tai, Heng-Ming The Korea Institute of Information and Commucation 2012 Journal of communications and networks Vol.14 No.5

Accurate and efficient estimation of the number of sources is critical for providing the parameter of targets in problems of array signal processing and blind source separation among other such problems. When conventional estimators work in unfavorable scenarios, e.g., at low signal-to-noise ratio (SNR), with a small number of snapshots, or for sources with a different strength, it is challenging to maintain good performance. In this paper, the detection limit of the minimum description length (MDL) estimator and the signal strength required for reliable detection are first discussed. Though a comparison, we analyze the reason that performances of classical estimators deteriorate completely in unfavorable scenarios. After discussing the limiting distribution of eigenvalues of the sample covariance matrix, we propose a new approach for estimating the number of sources which is based on a sequential hypothesis test. The new estimator performs better in unfavorable scenarios and is consistent in the traditional asymptotic sense. Finally, numerical evaluations indicate that the proposed estimator performs well when compared with other traditional estimators at low SNR and in the finite sample size case, especially when weak signals are superimposed on the strong signals.

Response improvement for In2O3–TiO2 thick film gas sensors

Mao Lin Zhang,Jian Ping Song,Zhan Heng Yuan,Cheng Zheng 한국물리학회 2012 Current Applied Physics Vol.12 No.3

In2O3 is introduced into TiO2 by sol-gel method to improve the response/recovery rate and expand the operating temperature, when the In2O3-TiO2 mixed system is exposed to H2/O2. The sensor is fabricated by thick film technology. Influence of In2O3 on the film phase composition, microstructure and sensing characteristics is discussed. Dynamic response properties show that the operating temperature of the mixed system is at 500e800 ℃, which is about 600e800 ℃ for pure TiO2. Response time of the sensor is about 200e260 ms (millisecond) while recovery time is in a narrow range of 60e280 ms at 600e800 ℃. The promoting mechanism is suggested to arise from the introduction of In2O3 and grain size effect of the sensing film. Then In2O3-TiO2 thick films are surface-modified by Pt using chloroplatinic acid. The promoting effect of Pt dispersed on the mixed system is also investigated. In2O3 is introduced into TiO2 by sol-gel method to improve the response/recovery rate and expand the operating temperature, when the In2O3-TiO2 mixed system is exposed to H2/O2. The sensor is fabricated by thick film technology. Influence of In2O3 on the film phase composition, microstructure and sensing characteristics is discussed. Dynamic response properties show that the operating temperature of the mixed system is at 500e800 ℃, which is about 600e800 ℃ for pure TiO2. Response time of the sensor is about 200e260 ms (millisecond) while recovery time is in a narrow range of 60e280 ms at 600e800 ℃. The promoting mechanism is suggested to arise from the introduction of In2O3 and grain size effect of the sensing film. Then In2O3-TiO2 thick films are surface-modified by Pt using chloroplatinic acid. The promoting effect of Pt dispersed on the mixed system is also investigated.