A digital signal processing type frequency locked loop for frequency shift keying demodulation

In this paper, we propose a digital signal processing type frequency locked loop (DSP-FLL) using a frequency difference detector (FDD). Since the DSP-FLL is controlled by the frequency, the pole of the voltage controlled oscillator vanishes in the baseband equivalent circuit. Therefore, the transfer function becomes first order and a ringing does not occur. Furthermore, it can be understood from the detection property of the FDD that a cycle slip does not occur and the DSP-FLL can pull in the frequency step input up to half of the sampling frequency.     

Protection relaying scheme based on fault reactance operation type

The theories of operation of existing relays are roughly divided into two types: the current differential type based on Kirchhoff's first law and the impedance type based on Kirchhoff's second law. We can use Kirchhoff's laws to rigorously formulate fault phenomena, so the circuit equations are represented as nonlinear simultaneous equations whose variables are the fault point k and the fault resistance R_f. This method has two defects: (1) a heavy computational burden in iterative calculation by the N‐R method and (2) the relay operator cannot easily understand the principle of numerical matrix operation. The new protection relay principles proposed in this paper focus on the fact that the reactance component at the fault point is close to zero. The reactances X_f(S) and X_f(R) at the ends of the branch are calculated by solution of linear equations. If the signs of X_f(S) and X_f(R) are not the same, it can be inferred that the fault point is located in the branch. This reactance X_f corresponds to the difference in branch reactance between the actual fault point and an imaginary fault point. Thus, the relay engineer can understand the fault location in terms of the concept of “distance.” Simulation results using this new method indicate that it can provide much more precise estimation of fault locations than those obtained by inspection of operating transmission lines. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 168(1): 29–40, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20720     

Interactive monitoring portal for fusion simulations

The Center for Simulation of RF Wave Interactions with Magnetohydrodynamics (SWIM) Project is a proto-Fusion Simulation Program (FSP) whose goal is to study high-performance fusion plasmas and perform comprehensive simulations that are essential to the development of fusion. SWIM team members are geographically distributed and utilize distributed supercomputers for computational simulations. Due to the highly distributed computational work environment, the SWIM team has the difficulty of monitoring code runs and discovering historical runs. To alleviate this difficulty a web-based monitoring portal has been developed and deployed.The monitoring portal tracks the progress of simulations and automatically collects metadata in real-time. This capability helps scientists to effectively utilize precious computer resources. Furthermore, the portal provides a web-based interface for post-run analysis, such as visualizing the results, logging the user comments, and rating the simulation quality. The user interface provides rapid discovery capability via multi-field searching and sorting.The development of the monitoring portal used open source software, such as Python, Django, MySQL, and Apache. It uses MDSplus for data management, Memcached for data caches, and OpenID for single sign-on security.This paper describes the software architecture, related technologies and deployment experiences of the monitoring portal.     

Giant Piezoresistive Effects in Single Grain Boundaries of Semiconducting Barium Titanate Ceramics*

Extremely large piezoresistive effects with a gage factor (elastoresistance) of > 1 × 10⁶ in single grain boundaries of thin ceramic bars of semiconducting barium titanate have been observed at room temperature. Thin barium titanate ceramic bars with a diameter in the range of 10 to 20 μm were prepared to consist of single grains joined together in series. Large piezoresistive effects were observed for some of the single grain boundaries in the present samples under compressive stresses, but no distinct piezoresistance was observed in the grain bulk. A giant piezoresistive effect with a gage factor of 3 × 10⁷ was observed for a single grain boundary which exhibited a saw-tooth type PTCR (positive temperature coefficient of resistivity) characteristic with a significantly large bias dependence of it. This demonstrates that the piezoresistive phenomenon may be interpreted in terms of the change of the potential barrier height due to the change of ferroelectric domain morphologies in the vicinity of grain boundaries under mechanical and electric stresses.     

Stratum Corneum Lipid Structure Investigated by EPR Spin-Probe Method: Application of Terpenes

Electron paramagnetic resonance (EPR) in conjunction with a slow-tumbling simulation was utilized for defining stratum corneum (SC) lipid structure. SC from the back of hairless mouse (HOS:HR-1) was stripped consecutively from one to three or four times using a glass plate coated with a cyanoacrylate resin. Aliphatic spin probes, 5-doxylstearic acid (5-DSA) and 3β-doxyl-5α-cholestane (CHL), were used to evaluate the SC ordering. EPR spectrum of 5-DSA incorporated in the SC demonstrated a characteristic peak for the first strip. A slow-tumbling simulation for 5-DSA showed clear differences in EPR intensities as well as ordering values (S ₀) of the SC for control and terpenes treated SC. The α-terpineol enhanced the permeation of the single chain 5-DSA about three times more than that of the control. However, EPR spectra of CHL in the SC did not show a clear difference for each strip, except for the signal intensity. The results imply that CHL permeates into SC lipid differently from 5-DSA. The enhancement of the 5-DSA is more significant than that of CHL. Therefore, the present results can be useful for various drug administrations via the skin.     

Operation Request Gatekeeper: a software system for remote access control of diagnostic instruments in fusion experiments

Tokamak diagnostic settings are repeatedly modified to meet the changing needs of each experiment. Enabling the remote diagnostic control has significant challenges due to security and efficiency requirements. The Operation Request Gatekeeper (ORG) is a software system that addresses the challenges of remotely but securely submitting modification requests. The ORG provides a framework for screening all the requests before they enter the secure machine zone and are executed by performing user authentication and authorization, grammar validation, and validity checks. A prototype ORG was developed for the ITER CODAC that satisfies their initial requirements for remote request submission and has been tested with remote control of the KSTAR Plasma Control System. This paper describes the software design principles and implementation of ORG as well as worldwide test results.     

Parallel phase-shifting digital holography with adaptive function using phase-mode spatial light modulator

Parallel phase-shifting digital holography using a phase-mode spatial light modulator (SLM) is proposed. The phase-mode SLM implements spatial distribution of phase retardation required in the parallel phase-shifting digital holography. This SLM can also compensate dynamically the phase distortion caused by optical elements such as beam splitters, lenses, and air fluctuation. Experimental demonstration using a static object is presented.     

Crystal Growth and Electrical Properties of Pb((Zn1/3Nb2/3)0.91Ti0.09)O3 Single Crystals Produced by Solution Bridgman Method

Piezoelectric Pb((Zn_1/3Nb_2/3)_0.91Ti_0.09)O₃ (PZNT 91/9) single crystals 40 mm in diameter were successfully grown from solution by the Bridgman method with a PbO flux. The crystals were grown in a platinum crucible heated to 1130°C. Growth rate was 0.35 mm/h. The obtained crystals were ~40 mm in diameter 20 mm in length and were a rust-brown color. The Curie temperature, T _C, ranged from 175° to 185°C, and the dielectric constant before poling at room temperature was 2000-8900 within a wafer. After electrical poling, specimens had electromechanical coupling coefficients in rectangular bar mode, k _33´, of 79%-88%, which were larger than for PZT ceramics ( k _33´ < 70%). These PZNT 91/9 single crystals grown by the Bridgman process satisfy the requirements for array-type transducers used in echocardiographic equipment. Results confirm that the Bridgman method is useful for mass-producing large crystals of PZNT 91/9.