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Pattern recognition using neural networks. Technical report, August 1, 1994--September 11, 1994

Description: I am pleased to submit the following technical report to Oak Ridge National Laboratories as an accomplishment of the 6 (six) week appointment in the U.S. Nuclear Regulatory Commission`s Historically Black College and Universities Faculty Research Participation Program, Summer 1994 (August - September 11, 1994). In this project, an approach for pattern recognition using neural networks is proposed. Particularly, a Boltzmann machine, a Hopfield neural net model, is used in pattern recognition with desirable learning ability. The Boltzmann machine features stochastic learning, which acts as the connection dynamics for determining the weights on the connections between the neuron-like cells (processing elements) of different layers in the neural network. An algorithm for pattern recognition using Boltzmann machine is also presented, which could be coded with C programming language or others to implement the approach for efficient pattern recognition. Finally, a follow-on research work derived from this project is planned if the author could win another summer appointment in 1995 from the Science/Engineering Education Division, Oak Ridge Institute for Science and Education, Oak Ridge National Laboratories.
Date: December 31, 1994
Creator: Ma, H.
Partner: UNT Libraries Government Documents Department

Surface radiation properties of ThO/sub 2/ and other reactor materials

Description: This technical report summarizes the results obtained on surface radiation properties of ThO/sub 2/ and other related reactor materials. Specifically, the present study provides surface radiation properties of three nuclear reactor materials; thorium dioxide, sodium and steel (99 Fe + 1 C). First, based on transmission spectra and Kramers-Kronig analysis, the complex refractive index, which is fundamental to surface radiation property calculations, of ThO/sub 2/ is presented over a wide spectral range. Then depending on the contacting media, three types of the surface are considered. They are the interfaces between ThO/sub 2/ and Sodium, ThO/sub 2/ and Steel (99 Fe + 1 C) as well as ThO/sub 2/ and a gas. For each interface, the spectral interface reflectance from one side of the medium to the other side is evaluated for all wavelengths.
Date: December 1, 1979
Creator: Chan, S.H. & Ma, H.H.
Partner: UNT Libraries Government Documents Department

The effect of beam intensity on the estimation bias of beam position

Description: For the signals of the beam position monitor (BPM), the signal-to-noise ratio (SNR) is directly related to the beam intensity. Low beam intensity results in poor SNR. The random noise has a modulation effect on both the amplitude and phase of the BPM signals. Therefore, the beam position measurement has a certain random error. In the currently used BPM, time-averaging and waveform clipping are used to improve the measurement. The nonlinear signal processing results in a biased estimate of beam position. A statistical analysis was made to examine the effect of the SNR, which is determined by the beam intensity, on the estimation bias. The results of the analysis suggest that the estimation bias has a dependence not only on the beam position but also on beam intensity. Specifically, the dependence gets strong as the beam intensity decreases. This property has set a lower limit of the beam intensity range which the BPM`s can handle. When the beam intensity is below that limit the estimation bias starts to vary dramatically, resulting in the BPMs failure. According to the analysis, the lowest beam intensity is that at which the SNR of the generated BPM signal is about 15 dB. The limit for NSEP BPM, for instance, is about 6Ell. The analysis may provide the BPM designers with some idea about the potential of the current BPM`S.
Date: September 1, 1994
Creator: Ma, H.
Partner: UNT Libraries Government Documents Department

Low-Level Radio Frequency System Development for the National Synchrotron Light Source II

Description: The National Synchrotron Light Source-II (NSLS-II) is a new ultra-bright 3GeV 3rd generation synchrotron radiation light source. The performance goals require operation with a beam current of 500mA and a bunch current of at least 0.5mA. The position and timing specifications of the ultra-bright photon beam imposes a set of stringent requirements on the performance of radio frequency (RF) control. In addition, commissioning and staged installation of damping wigglers and insertion devices requires the flexibility of handling varying beam conditions. To meet these requirements, a digital implementation of the LLRF is chosen, and digital serial links are planned for the system integration. The first prototype of the controller front-end hardware has been built, and is currently being tested.
Date: May 4, 2009
Creator: Ma,H. & Rose, J.
Partner: UNT Libraries Government Documents Department

SCIENTIFIC VISUALIZATION AND DATA MODELING OF SCATTERED SEDIMENT CONTAMINANT DATA IN NEW YORK/NEW JERSEY ESTUARIES.

Description: Sediments in many parts of the New York and New Jersey estuary system are contaminated with toxic organic and inorganic compounds by different sources. Because of the potential environmental consequences, detailed information on the spatial distribution of sediment contaminants is essential in order to carry out routine shipping channel dredging in an environmentally responsible way, and to remediate hot spots cost-effectively and safely. Scientific visualization and scatter data modeling techniques have been successfully applied in analyzing the sparse sampling data of sediment contaminants in New York and New Jersey estuaries, the underlying spatial characteristics of which are otherwise difficult to comprehend. Continuous realizations of contaminant concentrations in the region were obtained by using a spectral domain-decomposition scattered data model and IBM Data Explorer which is a software package for scientific data visualization.
Date: October 23, 1998
Creator: MA,H.; JONES,K.W. & STERN,E.A.
Partner: UNT Libraries Government Documents Department

A PARALLEL IMPLEMENTATION OF A SPECTRAL ELEMENT OCEAN MODEL FOR SIMULATING LOW-LATITUDE CIRCULATION SYSTEM

Description: This paper is about the parallel implementation of a high-resolution, spectral element, primitive equation model of a homogeneous equatorial ocean. The present work shows that the high-order domain decomposition methods can be efficiently implemented in a massively parallel computing environment to solve large-scale CFD problems, such as the general circulation of the ocean.
Date: November 1997
Creator: Ma, H.; McCaffrey, J. & Piacsek, S.
Partner: UNT Libraries Government Documents Department

MUON DECAY ASYMMETRIES FROM KOL YIELDS POM+M-DECAYS.

Description: We have examined the decay K{sub L}{sup 0} {yields} {pi}{sup 0} {mu}{sup +} {mu}{sup -} in which the branching ratio, the muon energy asymmetry and the muon decay asymmetry could be measured. In particular, we find that within the Standard Model the longitudinal polarization (PL) of the muon is proportional to the direct CP violating amplitude. On the other hand the energy asymmetry and the out-of-plane polarization (P{sub N}) depend on both indirect and direct CP violating amplitudes. Although the branching ratio is small and difficult to measure because of background, the asymmetries could be large {Omicron}(1) in the Standard Model. A combined analysis of the energy asymmetry, P{sub L} and P{sub N} could be used to separate indirect, CPV, direct CPV, and CP conserving contributions to the decay.
Date: June 12, 2001
Creator: DIWAN, M.V.; MA, H. & TRUEMAN, T.L.
Partner: UNT Libraries Government Documents Department

MASSIVELY PARALLEL IMPLEMENTATION OF A HIGH ORDER DOMAIN DECOMPOSITION EQUATORIAL OCEAN MODEL

Description: The present work is about the algorithms and parallel constructs of a spectral element equatorial ocean model. It shows that high order domain decomposition ocean models can be efficiently implemented on massively parallel architectures, such as the Connection Machine Model CM5. The optimized computational efficiency of the parallel spectral element ocean model comes not only from the exponential convergence of the numerical solution, but also from the work-intensive, medium-grained, geometry-based data parallelism. The data parallelism is created to efficiently implement the spectral element ocean model on the distributed-memory massively parallel computer, which minimizes communication among processing nodes. Computational complexity analysis is given for the parallel algorithm of the spectral element ocean model, and the model's parallel performance on the CM5 is evaluated. Lastly, results from a simulation of wind-driven circulation in low-latitude Atlantic ocean are described.
Date: July 15, 1998
Creator: MA,H.; MCCAFFREY,J.W. & PIACSEK,S.
Partner: UNT Libraries Government Documents Department

SCIENTIFIC VISUALIZATION AND DATA MODELING OF SCATTERED SEDIMENT CONTAMINANT DATA IN NEW YORK/NEW JERSEY ESTUARIES

Description: Sediments in many parts of the New York and New Jersey estuary system are contaminated with toxic organic and inorganic compounds by different sources. Because of the potential environmental consequences, detailed information on the spatial distribution of sediment contaminants is essential in order to carry out routine shipping channel dredging in an environmentally responsible way, and to remediate hot spots cost-effectively and safely. Scientific visualization and scatter data modeling techniques have been successfully applied in analyzing the sparse sampling data of sediment contaminants in New York and New Jersey estuaries, the underlying spatial characteristics of which are otherwise difficult to comprehend. Continuous realizations of contaminant concentrations in the region were obtained by using a spectral domain-decomposition scattered data model and IBM Data Explorer which is a software package for scientific data visualization.
Date: October 23, 1998
Creator: MA,H.; JONES,K.W. & STERN,E.A.
Partner: UNT Libraries Government Documents Department

THE Low-level Radio Frequency System for the superconducting cavities of National Synchrotron Light Source II

Description: A digital low-level radio frequency (LLRF) field controller has been developed for the storage ring of The National Synchrotron Light Source-II (NSLS-II). The primary performance goal for the LLRF is to support the required RF operation of the superconducting cavities with a beam current of 500mA and a 0.14 degree or better RF phase stability. The digital field controller is FPGA-based, in a standard format 19-inch/I-U chassis. It has an option of high-level control support with MATLAB running on a local host computer through a USB2.0 port. The field controller has been field tested with the high-power superconducting RF (SRF) at Canadian light Source, and successfully stored a high beam current of 250 mA. The test results show that required specifications for the cavity RF field stability are met. This digital field controller is also currently being used as a development platform for other functional modules in the NSLS-II RF systems.
Date: March 28, 2011
Creator: Ma, H.; Rose, J.; Holub, B.; Cupolo, J.; Oliva, J.; Sikora, R. et al.
Partner: UNT Libraries Government Documents Department

NSLS-II RF SYSTEMS

Description: The NSLS-II is a new third generation light source being constructed at Brookhaven Lab. The storage ring is optimized for low emittance by use of damping wigglers to reduce the emittance to below 1 nm-rad. The RF systems are designed to provide stable beam through tight RF phase and amplitude stability requirements.
Date: March 28, 2011
Creator: Rose, J.; Gash, W.; Holub, B.; Kawashima, Y.; Ma, H.; Towne, N. et al.
Partner: UNT Libraries Government Documents Department

Massively parallel implementation of a high order domain decomposition equatorial ocean model

Description: The present work is about the algorithms and parallel constructs of a spectral element equatorial ocean model. It shows that high order domain decomposition ocean models can be efficiently implemented on massively parallel architectures, such as the Connection Machine Model CM5. The optimized computational efficiency of the parallel spectral element ocean model comes not only from the exponential convergence of the numerical solution, but also from the work-intensive, medium-grained, geometry-based data parallelism. The data parallelism is created to efficiently implement the spectral element ocean model on the distributed-memory massively parallel computer, which minimizes communication among processing nodes. Computational complexity analysis is given for the parallel algorithm of the spectral element ocean model, and the model's parallel performance on the CM5 is evaluated. Lastly, results from a simulation of wind-driven circulation in low-latitude Atlantic Ocean are described.
Date: June 1, 1999
Creator: Ma, H.; McCaffrey, J.W. & Piacsek, S.
Partner: UNT Libraries Government Documents Department

ELECTROMAGNETIC FIELD MEASUREMENT OF FUNDAMENTAL AND HIGHER-ORDER MODES FOR 7-CELL CAVITY OF PETRA-II

Description: The booster synchrotron for NSLS-II will include a 7-cell PETRA cavity, which was manufactured for the PETRA-II project at DESY. The cavity fundamental frequency operates at 500 MHz. In order to verify the impedances of the fundamental and higher-order modes (HOM), which were calculated by computer code, we measured the magnitude of the electromagnetic field of the fundamental acceleration mode and HOM using the bead-pull method. To keep the cavity body temperature constant, we used a chiller system to supply cooling water at 20 degrees C. The bead-pull measurement was automated with a computer. We encountered some issues during the measurement process due to the difficulty in measuring the electromagnetic field magnitude in a multi-cell cavity. We describe the method and apparatus for the field measurement, and the obtained results.
Date: March 28, 2011
Creator: Kawashima, Y.; Blednykh, A.; Cupolo, J.; Davidsaver, M.; Holub, B.; Ma, H. et al.
Partner: UNT Libraries Government Documents Department

An atomic force microcopy study of the mechanical and electricalproperties of monolayer films of molecules with aromatic end groups

Description: The effect of intermolecular {pi}-{pi} stacking on the electrical and mechanical properties of monolayer films molecules containing aromatic groups was studied using atomic force microscopy. Two types of aromatic molecules, (4-mercaptophenyl) anthrylacetylene (MPAA) and (4-mercaptophenyl)-phenylacetylene (MPPA) were used as model systems with different {pi}-{pi} stacking strength. Monolayer films of these molecules on Au(111) surfaces exhibited conductivities differing by more than one order of magnitude, MPAA being the most conductive and MPPA the least conductive. The response to compressive loads by the AFM tip was also found to be very different for both molecules. In MPAA films distinct molecular conductivity changes are observed upon mechanical perturbation. This effect however was not observed on the MPPA film, where intermolecular {pi}-{pi} interactions are likely weaker.
Date: September 6, 2007
Creator: Fang, Liang; Park, J.Y.; Ma, H.; Jen, A.K.-Y. & Salmeron, M.
Partner: UNT Libraries Government Documents Department

UPDATE E923 - SEARCH FOR T VIOLATING MUON POLARIZATION IN K+ YIELDS M+P0VM DECAY.

Description: This is an update to the E923 proposal for a new search for the time reversal violating polarization of the muon normal to the decay plane of the K{sup +} {r_arrow} {mu}{sup +}{pi}{sup 0}{nu} decay. The value of such polarization in the Standard Model is zero. However, it is now accepted that the baryon asymmetry of the universe requires a source of CP violation stronger than that embodied in the quark mixing matrix. Models of non-standard CP violation that produce the baryon asymmetry could also produce effects observable in the transverse polarization. The very high sensitivity of the experiment makes this search interesting and timely. In this update we discuss the possibility of additional kaon decay measurements with the same apparatus as well as the detector development over the last year. In particular, we show that we will be able to measure the T-violating muon polarization in K{sup +} {r_arrow} {mu}{sup +}{nu}{gamma} decays. Such a measurement is complimentary to the main goal of this experiment. We also show that we will obtain a large sample of K{sup +} {r_arrow} {pi}{sup +}{pi}{sup 0}{gamma} events that can be used to understand kaon structure and test the detailed predictions from Chiral Perturbation Theory.
Date: October 8, 1998
Creator: CARROLL,A.; DIWAN,M.V.; FRANK,J.; GORDEEV,A.; KETTELL,S.; LEIPUNER,L. et al.
Partner: UNT Libraries Government Documents Department

A measurement of E/. pi. for a fast lead liquid argon calorimeter

Description: The NA34 (HELIOS) calorimeter has measured e/{pi} {congruent} 1.1 in a uranium/liquid argon calorimeter with a shaping time of 135 nsec. Lead may be a viable alternative, but e/{pi} must first be measured at fast shaping times in lead. We re preparing to measure e/{pi} at momenta ranging from 0.5 to 20 GeV/c and with shaping times of 50, 100 and 150 nsec.
Date: January 1, 1990
Creator: Makowiecki, D.; Gordon, H.A.; Ma, H.; Murtagh, M.; Radeka, V.; Rahm, D. et al.
Partner: UNT Libraries Government Documents Department

A measurement of E/{pi} for a fast lead liquid argon calorimeter

Description: The NA34 (HELIOS) calorimeter has measured e/{pi} {congruent} 1.1 in a uranium/liquid argon calorimeter with a shaping time of 135 nsec. Lead may be a viable alternative, but e/{pi} must first be measured at fast shaping times in lead. We re preparing to measure e/{pi} at momenta ranging from 0.5 to 20 GeV/c and with shaping times of 50, 100 and 150 nsec.
Date: December 31, 1990
Creator: Makowiecki, D.; Gordon, H. A.; Ma, H.; Murtagh, M.; Radeka, V.; Rahm, D. et al.
Partner: UNT Libraries Government Documents Department

Status of the Short-Pulse X-ray Project at the Advanced Photon Source

Description: The Advanced Photon Source Upgrade (APS-U) Project at Argonne will include generation of short-pulse x-rays based on Zholents deflecting cavity scheme. We have chosen superconducting (SC) cavities in order to have a continuous train of crabbed bunches and flexibility of operating modes. In collaboration with Jefferson Laboratory, we are prototyping and testing a number of single-cell deflecting cavities and associated auxiliary systems with promising initial results. In collaboration with Lawrence Berkeley National Laboratory, we are working to develop state-of-the-art timing, synchronization, and differential rf phase stability systems that are required for SPX. Collaboration with Advanced Computations Department at Stanford Linear Accelerator Center is looking into simulations of complex, multi-cavity geometries with lower- and higher-order modes waveguide dampers using ACE3P. This contribution provides the current R&D status of the SPX project.
Date: July 2012
Creator: Nassiri, A.; Berenc, T. G.; Borland, M.; Brajuskovic, B.; Bromberek, D. J.; Carwardine, J. et al.
Partner: UNT Libraries Government Documents Department