Structure-Exploiting Delay-Dependent Stability Analysis Applied to Power System Load Frequency Control

Linear matrix inequality (LMI) based delay-dependent stability analysis/synthesis methods have been applied to power system load frequency control (LFC) which has communication networks in its loops. However, the computational burden of solving large-scale LMIs poses a great challenge to the application of those methods to real-world power systems. This paper investigates the computational aspect of delay-dependent stability analysis (DDSA) of LFC. The basic idea is to improve the numerical tractability of DDSA by exploiting the chordal sparsity and symmetry of the graph related to LFC loops. The graph-theoretic analysis yields the structure restrictions of weighting matrices needed for the LMIs to inherit the chordal sparsity of the control loops. By enforcing those structure restrictions on weighting matrices, the positive semidefinite constraints in the LMIs can be decomposed into smaller ones, and the number of decision variables can be greatly reduced. Symmetry in LFC control loops is also exploited to reduce the number of decision variables. Numerical studies show the proposed structure-exploiting techniques significantly improves the numerical tractability of DDSA at the cost of the introduction of acceptable minor conservatism

THE ACUTE EFFECT OF WHOLE BODY VIBRATION TRAINING ON AGILITY, SPEED AND POWER IN MALE VOLLEYBALL PLAYERS

The purpose of this study was to examine the acute effect of whole body vibration training on agility, speed and power in male volleyball players. Ten college volleyball players volunteered to participate in this study. The vibration training (VT) consisted of 60% with 28 Hz frequencies and 1Omm amplitudes. Counter movement jump (CMJ), blocking agility test (BAT), agility test (AT) and 10 meters sprinting (1 OMS) were performed at pre-test and post-test (60s rest). The peak force (PF). mean force (MF), maximum rate of force development (mRFD) and relative net impulse (RNI) from the CMJs were computed. A repeated measures ANOVA was applied to obtain the variables. The present study indicated that the WBV significantly improves the MF, mRFD and BAT parameters of CMJ and BAT performances excluding the PF. Speed and agility does not seem to be enhanced by VT

Flexible Macroblock Ordering Scramble Encryption Techniques for H.264/AVC Videos

In this paper, a new video encryption method through scrambling the compressed videos is presented, which is targeted for H.264/AVC video encryptionin order to provide the greatest content protection in the compressed domain.The proposed algorithm uses a macroblock switching mechanism to scramble the video contentfor the compressed video sequences. Only the instantaneous decoded reference (IDR) pictures are scrambled to take the advantage of drift error propagation from all the inter-prediction frames. The proposed encryption technique is designed to perform after the encoding process on the compressed bitstream such that bitstream is modified by the parser directly. Finally,the scrambled video is still format-compliant to a general H.264/AVC decoder and can only be recovered by the authorized user that owns private key. Based on experimental results, the scene in the scrambled video can be effectively protected by the proposed scheme with low computational complexity and negligiblebitrate overhead

Functional analysis of novel SNPs and mutations in human and mouse genomes

<p>Abstract</p> <p>Background</p> <p>With the flood of information generated by the new generation of sequencing technologies, more efficient bioinformatics tools are needed for in-depth impact analysis of novel genomic variations. FANS (Functional Analysis of Novel SNPs) was developed to streamline comprehensive but tedious functional analysis steps into a few clicks and to offer a carefully designed presentation of results so researchers can focus more on thinking instead of typing and calculating.</p> <p>Results</p> <p>FANS <url>http://fans.ngc.sinica.edu.tw/</url> harnesses the power of public information databases and powerful tools from six well established websites to enhance the efficiency of analysis of novel variations. FANS can process any point change in any coding region or GT-AG splice site to provide a clear picture of the disease risk of a prioritized variation by classifying splicing and functional alterations into one of nine risk subtypes with five risk levels.</p> <p>Conclusion</p> <p>FANS significantly simplifies the analysis operations to a four-step procedure while still covering all major areas of interest to researchers. FANS offers a convenient way to prioritize the variations and select the ones with most functional impact for validation. Additionally, the program offers a distinct improvement in efficiency over manual operations in our benchmark test.</p

Chromatographic determination of siphonodin content: A rapid and simple strategy for discriminating between Hemsleya omeiensis and other sources of Xuedan

Purpose: To develop a rapid and simple siphonodin content-based high performance liquid chromatography (HPLC) method to distinguish Hemsleya omeiensis from other sources of xuedan. Methods: Siphonodin was isolated from Hemsleya omeiensis and identified by x-ray crystallographic analysis. An optimized HPLC method was applied for the determination of siphonodin contents of H. omeiensis, H. dolichocarpa and H. gigantha. Results: Siphonodin was successfully separated by the optimized HPLC method in &lt; 10 min, and the results of validation showed that the HPLC method was stable and very accurate for the quantification of siphonodin. The mean content of siphonodin in 10 batches of H. omeiensis was 3.78 mg/g, but the compound was not detectable in H. dolichocarpa and H. gigantha using the developed HPLC method. Conclusion: These results indicate that the developed HPLC method is suitable for distinguishing H. omeiensis from other sources of xuedan

Design of robust MPPT controller for grid-connected PMSG-Based wind turbine via perturbation observation based nonlinear adaptive control

This paper presents a robust maximum power point tracking (MPPT) control scheme for a grid-connected permanent magnet synchronous generator based wind turbine (PMSG-WT) using perturbation observation based nonlinear adaptive control. In the proposed control scheme, system nonlinearities, parameter uncertainties, and external disturbances of the PMSG-WT are represented as a lumped perturbation term, which is estimated by a high-gain perturbation observer. The estimate of the lumped perturbation is employed to compensate the actual perturbation and further achieve adaptive feedback linearizing control of the original nonlinear system, without requiring the detailed system model and full state measurements. The effectiveness of the proposed control scheme is verified through both simulation studies and experimental tests. The results show that, compared with the conventional vector controller and the standard feedback linearizing controller, the proposed control strategy provides higher power conversion efficiency and has better dynamic performances and robustness against parameter uncertainties and external disturbances