Balancing control for dispersed generators considering torsional torque suppression and AVR performance for synchronous generators

Electric utility deregulation enabled PPSs (Power Producers and Suppliers) to enter the electricity market. PPSs are supposed to achieve 30‐minute balancing control for stable power supply of electric power. In addition, load rejection and instantaneous voltage drops greatly affect turbine shafting, that is, torsional torque oscillation. Therefore, PPSs must consider a reduction of torsional torque in order to prevent generator shaft damage. This paper proposes a control system which allows the achievement of both 30‐minute balancing control and reduction of torsional torque by using an H_∞ controller. The effectiveness of the proposed controller is validated by using MATLAB. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 170(1): 16–25, 2010; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20868     

Improvement of islet culture with sericin

Islet transplantation is a promising treatment for diabetes. Serum is a necessary supplement in islet cultures, but it has various disadvantages including the risk of contamination by several pathogens. Results of this study suggest that sericin is a useful alternative supplement. Sericin accelerated the proliferation of the rat insulinoma cell line RIN-5F and improved the serum-free culture of rat islets.     

A reliable method for classification of bank notes using artificial neural networks

We present a method based on principal component analysis (PCA) for increasing the reliability of bank note recognition machines. The system is intended for classifying any kind of currency, but in this paper we examine only US dollars (six different bill types). The data was acquired through an advanced line sensor, and after preprocessing, the PCA algorithm was used to extract the main features of data and to reduce the data size. A linear vector quantization (LVQ) network was applied as the main classifier of the system. By defining a new method for validating the reliability, we evaluated the reliability of the system for 1200 test samples. The results show that the reliability is increased up to 95% when the number of PCA components as well as the number of LVQ codebook vectors are taken properly. In order to compare the results of classification, we also applied hidden Markov models (HMMs) as an alternative classifier. This work was presented, in part, at the 8th International Symposium on Artificial Life and Robotics, Oita, Japan, January 24#x2013;26, 2003     

Prediction of protein-protein interaction sites using support vector machines

The identification of protein-protein interaction sites is essential for the mutant design and prediction of protein-protein networks. The interaction sites of residue units were predicted using support vector machines (SVM) and the profiles of sequentially/spatially neighboring residues, plus additional information. When only sequence information was used, prediction performance was highest using the feature vectors, sequentially neighboring profiles and predicted interaction site ratios, which were calculated by SVM regression using amino acid compositions. When structural information was also used, prediction performance was highest using the feature vectors, spatially neighboring residue profiles, accessible surface areas, and the with/without protein interaction sites ratios predicted by SVM regression and amino acid compositions. In the latter case, the precision at recall = 50% was 54-56% for a homo-hetero mixed test set and >20% higher than for random prediction. Approximately 30% of the residues wrongly predicted as interaction sites were the closest sequentially/spatially neighboring on the interaction site residues. The predicted residues covered 86-87% of the actual interfaces (96-97% of interfaces with over 20 residues). This prediction performance appeared to be slightly higher than a previously reported study. Comparing the prediction accuracy of each molecule, it seems to be easier to predict interaction sites for stable complexes.     

Laboratory model tests and FE analyses on tunneling in the unconsolidated ground with inclined layers

Tunneling model tests are performed in an unconsolidated ground with inclined artificial layers. In order to simulate the model ground with inclined layers, aluminum rods and aluminum blocks are used. Three kinds of formations are introduced for the inclined-layer ground, namely, the 30° formation simulates a ground with lowly inclined layers, the 60° formation with highly inclined layers and the 90° formation simulates a ground with vertical layers. Tunneling process is simulated with a two-dimensional trapdoor apparatus. The 60° formation shows the most significant feature on the non-symmetrical distribution of the earth pressure. For this formation, the outer right part shows a greater concentration of earth pressure than the outer left part of the trapdoor. Simultaneously, the upper left part, for which lateral earth pressure is reduced, shows greater loads than the upper right part of the trapdoor. A numerical simulation by the FE analysis is conducted, using joint elements, to portray the discontinuous behaviors of the model ground, in order to verify the experimental results. By calculating the distributions of earth pressure and surface profiles with the trapdoor displacement, it is confirmed that the calculated results can reasonably portray the experimental results within lower displacements of approximately 1.00 mm.     

Finite element analyses of near-tip deformation in inhomogeneous elastic-plastic fracture specimens

Two types of path-independent expressions were derived for the nonlinear fracture parameter T^* integral in inhomogeneous multilayer materials. Finite element analyses were carried out for inhomogeneous elastic-plastic fracture specimens consisting of A533B steel and HT80 steel: these two materials have considerably different yield stresses, although their elastic properties are exactly the same. The T^*-integral for inhomogeneous materials demonstrated excellent path independence even in the stages of large deformations around the crack tip and material interfaces. Numerically generated moiré fringe patterns are in good agreement with experimentally recorded patterns. The shapes of plastic zones appearing in the specimens reveal large inhomogeneity effects. The applicability of a hybrid moiré-finite element method is demonstrated briefly.     

BIO‐MOLECULAR EVENT EXTRACTION WITH MARKOV LOGIC

This article presents a novel approach to event extraction from biological text using Markov Logic. It can be described by three design decisions: (1) instead of building a pipeline using local classifiers, we design and learn a joint probabilistic model over events in a sentence; (2) instead of developing specific inference and learning algorithms for our joint model, we apply Markov Logic, a general purpose Statistical Relation Learning language, for this task; (3) we represent events as relations over the token indices of a sentence, as opposed to structures that relate event entities to gene or protein mentions. In this article, we extend our original work by providing an error analysis for binding events. Moreover, we investigate the impact of different loss functions to precision, recall and F‐measure. Finally, we show how to extract events of different types that share the same event clue. This extension allowed us to improve our performance our performance even further, leading to the third best scores for task 1 (in close range to the second place) and the best results for task 2 with a 14% point margin.     

Continuous fatigue level estimation for the classification of fatigued bills based on an acoustic signal feature by a supervised SOM

Fatigued bills have a harmful influence on the daily operation of automated teller machines (ATMs). To make the classification of fatigued bills more efficient, the development of an automatic fatigued bill classification method with a continu ous fatigue level is desirable. We propose a new method to estimate the bending rigidity of bills using the acoustic signal feature of banking machines. The estimated bending rigidities are used as the continuous fatigue level for the classification of fatigued bills. By using a supervised self-organizing map (SOM), we effectively estimate the bending rigidity using only the acoustic energy pattern. The experimental results with real bill samples show the effectiveness of the proposed method. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Nonlinear optical transmission of silk/green fluorescent protein (GFP) films

In this initial work, we demonstrate a technique for preparing thin (10-20 μm) films of silk doped with green fluorescent protein (GFP) by casting/annealing at 20 °C and describe the resulting film characteristics. Notably, the GFP molecules maintain their nonlinear optical properties as evidenced by two-photon fluorescence microscopy and two-photon absorption measurements using near-infrared femtosecond pulses. The fractional transmission of focused near-infrared pulses of 775 nm wavelength, 140 fs pulsewidth was observed to decrease as the incident pulse energy is increased and/or the incident spot size is decreased, indicating that nonlinear absorption is taking place. Visible damage from the pulses is observed in a ∼10 μm film at the highest peak incident fluences, which were in the range of 0.1-0.2 J/cm². Variations in thickness, morphology and GFP concentration of the films make precise specification of the two-photon absorption coefficient difficult. Since these films have potential applications in photonics, we suggest techniques for improving these properties in future generations of films. The suggestions present opportunities for future work.     

Fluid flow and heat transfer in the transition process of natural convection over an inclined plate

The present study deals with fluid flow and heat transfer in the transition process of natural convection over an inclined plate. In order to examine the mechanism of the transition process, experiments on the flow and heat transfer were performed for various plate inclination angles in the range of 20 to 75°. The wall temperature and fluid flow fields were visualized using a liquid crystal sheet and fluorescent paint, respectively. The visualization confirmed that separation of a boundary layer flow took place, and the onset point of streaks appeared over the plate wall when the modified Rayleigh number exceeded a characteristic value for each inclination angle. The local Nusselt number in the transition range was proportional to the one‐third power of the local modified Rayleigh number. By introducing a nondimensional parameter, a new correlation between visualizations of the flow and temperature fields and heat transfer was proposed. © 2001 Scripta Technica, Heat Trans Asian Res, 30(8): 648–659, 2001