bluuebunny/crossref_metadata_2025 huggingface dataset:
Validation of Computer Models for Nuclear Material Shipping Packages
Authors: Gupta Narendra K. , Shine Eugene P. , Tuckfield Richard C. , Fong Jeffrey T.
Published: August 2009

Computer models are abstractions of physical reality and are routinely used for solving practical engineering problems. These models are prepared using large complex computer codes that are widely used in the industry. Patran/Thermal is such a finite element computer code that is used for solving complex heat transfer problems in the industry. Finite element models of complex problems involve making assumptions and simplifications that depend upon the complexity of the problem and upon the judgment of the analysts. The assumptions involve mesh size, solution methods, convergence criteria, material properties, boundary conditions, etc. that could vary from analyst to analyst. All of these assumptions are, in fact, candidates for a purposeful and intended effort to systematically vary each in connection with the others to determine there relative importance or expected overall effect on the modeled outcome. These kinds of models derive from the methods of statistical science and are based on the principles of experimental designs. These, as all computer models, must be validated to make sure that the output from such an abstraction represents reality [1,2]. A new nuclear material packaging design, called 9977, which is undergoing a certification design review, is used to assess the capability of the Patran/Thermal computer model to simulate 9977 thermal response. The computer model for the 9977 package is validated by comparing its output with the test data collected from an actual thermal test performed on a full size 9977 package. Inferences are drawn by performing statistical analyses on the residuals (test data – model predictions).
Damage Behavior of Joined Fiber-Reinforced Polymer Pipe Under Monotonic and Cyclic Loading
Authors: Mertiny Pierre , Ursinus Kerstin
Published: August 2009

Fiber-reinforced polymer composite pipe may provide superior performance in terms of weight and corrosion resistance compared to structures made from conventional engineering materials. Using advanced winding techniques and adhesive bonding, composite tubes of high quality can be manufactured and joined in a cost effective manner. However, the current understanding of the damage mechanisms and long-term behavior of the tubes and joints is limited, thus the prediction of composite pipe performance is currently inadequate. Prior to developing modeling and failure prediction methodologies, it is imperative to identify and describe the types and evolution of damage associated with these structures. The present study is concerned with the monotonic and cyclic damage behavior of adhesively bonded glass-fiber reinforced epoxy polymer tubes. Experimental analyses on small-scale and large-scale specimens were conducted, and results revealed characteristic damage modes for the pipe body and the joint area. It was observed that damage modes and their severity depended on the applied biaxial pipe stress ratio and the type of loading (monotonic or cyclic).
Prediction of Fatigue Initiation Life of 16MnR Notched Components
Authors: Qiu Baoxiang , Gao Zengliang , Wang Xiaogui , Jiang Yanyao
Published: August 2009

Fatigue initiation life of smooth and notched rod 16MnR specimens subjected to fully reversed uniaxial tension-compression and pure torsion cyclic loading was studied by a multiaxial fatigue damage criterion. A robust cyclic plasticity model was implemented into ABAQUS via a user-material subroutine UMAT. In virtue of the axisymmetry of geometry and loading, an axisymmetric model was facilitated to get the cyclic elasto-plastic stress-strain relationship. The accumulated fatigue damage of each material point in different material plane was then obtained by Jiang’s fatigue damage criterion. From the results of fatigue damage analysis we know that the maximum stabilized damage per loading cycle was at the root of the notch, where the material point firstly reaches the critical damage value. Fatigue crack initiation life is defined as the ratio of the critical damage to the maximum fatigue damage per loading cycle. Uniaxial and pure torsion fatigue experiments for the smooth rod specimens, sharp and blunt notched rod specimens were also conducted. Good agreement was achieved by comparing the predicted fatigue initiation life with the experiment results.
Fractal Finite-Element Based Continuum Shape Sensitivity Analysis of Cracks
Authors: Rao B. N. , Reddy R. M.
Published: August 2009

Probabilistic fracture mechanics (PFM) that blends the theory of fracture mechanics and the probability theory provides a more rational means to describe the actual behavior and reliability of structures. However in PFM, the fracture parameters and their derivatives are often required to predict the probability of fracture initiation and/or instability in cracked structures. The calculation of the derivatives of fracture parameters with respect to load and material parameters, which constitutes size-sensitivity analysis, is not unduly difficult. However, the evaluation of response derivatives with respect to crack size is a challenging task, since it requires shape sensitivity analysis. Using a brute-force type finite-difference method to calculate the shape sensitivities is often computationally expensive, in that numerous repetitions of deterministic finite element analysis may be required for a complete reliability analysis. Therefore, an essential need of probabilistic fracture-mechanics is to evaluate the sensitivity of fracture parameters accurately and efficiently.
Seismic and Concurrent Load Design Criteria for Buried High Density Polyethylene Pipe in ASME BPVC Section III, Division 1, Applications: Part I — Piping Design Basis Criteria
Authors: Adams Timothy M. , Spanner Jack , Scavuzzo Rudolph J. , Thomas George Gary
Published: August 2009

The commercial Light Water Reactors operating within the United States have been in service from about 20 to 35 years. These plants include buried Service Water piping systems primarily made from low carbon steel. This piping has been subject to aging over the years, resulting in degradation and corrosion that will require replacement of the piping. Due to the advantageous cost and durability of High Density Polyethylene (HDPE) piping (as demonstrated in other commercial industries), ASME code inclusion of this piping is logical. Duke Power industry has expressed interest in replacing a portion of their steel buried Service Water Piping in Nuclear Power Stations with HDPE pipe. To assist in this effort EPRI has funded and supported the work summarized in this paper to develop design criteria for HPDE Pipe and has teamed with EPRI to develop appropriate ASME Code requirements. Other nuclear utilities will follow once HDPE piping is included in the ASME Code. This paper includes proposed allowable limits of all modes of failure and provides design criteria for HDPE pipe made from PE 3408 resin. It also provides the technical basis for the proposed criteria. This paper deals primarily with the actual design of the piping. The methods included comply with ASME Power Piping Code, B31.1-2004 and Section III of the ASME Boiler and Pressure Vessel Code. Extensive use was made of industrial research, data and experience over 40 years of use of high-density polyethylene piping. Allowable stresses are based on data published in these sources for Design and Service Levels A-D.
Seismic and Concurrent Load Design Criteria for Buried High Density Polyethylene Pipe in ASME BPVC Section III, Division 1, Applications: Part II — Piping Soil Interaction Design Basis Criteria
Authors: Thomas George Gary , Spanner Jack R. , Scavuzzo Rudolph J. , Adams Timothy M.
Published: August 2009

The commercial Light Water Reactors operating within the United States have been in service from about 20 to 35 years. These plants include buried Service Water piping systems primarily made from low carbon steel. This piping at several plants has been subject to aging over the years, resulting in degradation and corrosion that may require replacement of the piping. Due to the advantageous cost and durability of High Density Polyethylene (HDPE) piping (as demonstrated in other commercial industries), the nuclear power industry has expressed interest in replacing steel buried Service Water Piping in Nuclear Power Stations with HDPE Pipe. To assist in this effort EPRI has funded and supported the work summarized in this paper to develop design criteria for HPDE Pipe. The paper provides design criteria for High Density Polyethylene (HDPE) pipe made from PE 3408 resin. It also provides the technical basis for the proposed criteria. This paper deals primarily with the design of the piping in relation to its interface with the soil in which it is buried. The criteria primarily is derived from current analysis methodology for steel and concrete buried pipe while incorporating changes required to account for the properties and behavior of HDPE pipe. The proposed analysis methodology described herein has evolved into a proposed ASME Boiler and Pressure Vessel Code, Section III, Division I, Design Code Case for consideration by the Section III, Subcommittee on Nuclear Power.
Several Problems in Strength Testing of High Grade HSAW Pipe
Authors: Xiong Qingren , Feng Yaorong , Huo Chunyong , Li Jike , Yang Peng
Published: August 2009

Tensile property is the most important and basic property parameter, which is the base of pipeline design and safety assessment. This paper analyzes several issues such as the type of specimen and the test procedure, which occur during the strength testing of X80 HSAW pipe. It is presented that the yield strength value of base metal in transverse direction of X80 HSAW pipe from different kinds of specimen may be affected by many factors, such as Bauschinger effect, deformation strengthening effect and microstructure etc. It is suggested that the total elongation for high grade HSAW pipe in total extension under load method should be verified by ring expansion test.
Application of Earthquake Experienced Data to the Evaluation of Mechanical Equipment and Piping Systems: An Overview and Summary
Authors: Adams Timothy M.
Published: August 2009

In the early 1980’s, the Seismic Qualification Utility Group (SQUG) was formed to develop a generic methodology to disposition Unresolved Safety Issue USI A-46. Working in conjunction with the regulatory authorities and industry, SQUG developed a methodology and procedure to apply earthquake experience data to demonstrate the seismic ruggedness of electrical and mechanical equipment for resolution of USI A46. In the early 1990’s, QME Main Committee formed the Subgroup on Dynamic Qualification (SGDQ) to include a prescriptive methodology in the QME-1 Standard to apply actual earthquake experience to seismic qualification of mechanical equipment. For the past fifteen to twenty years, extensive data has been assembled on the actual performance of piping systems when subjected to strong motion earthquakes. This data has been compiled and assembled by several organizations and presented in various publications. In addition, several organizations developed procedures to apply this “experience” data to the seismic evaluation for piping systems in various applications. This paper provides an overview of application of actual earthquake experience data to the evaluation of mechanical equipment and piping systems.
Numerical Simulation of Ductile Crack Growth in Pipeline Steels
Authors: Wang Xin , Roy George , Xu Su , Tyson William R.
Published: August 2009

This paper presents numerical studies on stable crack extension of high toughness gas pipeline steels (X80) using the 2D and 3D computational cell approach. The Gurson-Tvergaard dilatant plasticity model for voided materials is used to describe the degradation of material stress capacity. Fixed-size, computational cell elements defined over a thin layer at the crack plane provide an explicit length scale for the continuum damage process. Outside this layer, the material is modeled as undamaged by void growth. The key micro-mechanics parameters are D, the thickness of the computational cell layer, and ƒ0, the initial cell porosity. Calibration of these parameters is conducted using analysis of ductile tearing from testing of Charpy-sized bending specimens. The resulting computational model enables the study of effects on crack growth of specimen size, geometry and loading mode. Computational and experimental studies are described for shallow and deep DWTT (drop weight tear test) specimens under quasi-static loading conditions.
Validation of a Model Material to Study Flaw Characterisation in Cleavage
Authors: Bezensek B.
Published: August 2009

Multiple or complex flaws are typically assessed using flaw assessment procedures, such as BS7910 [1] or ASME Boiler code, Section XI [2]. Such procedures may involve replacing real flaws with simplified flaws in a process of flaw characterisation. Recent work by Bezensek and Hancock [3,4] and Wilkes [5] demonstrated potential lack of conservatism in flaw characterisation procedure when applied to brittle fracture from complex flaws forming a re-entrant sector. In this paper a novel technique is discussed to study flaw characterisation in cleavage. The technique consists of exposing a transparent model material to a controlled thermal shocks produced by a high power laser. The shock locally cracks the material and produces an embedded crack. The objective of the current work is to validate the technique and the model material by performing fracture tests on configurations with twin and complex flaws and corresponding bounding semi-elliptical flaws using Perspex as a model material. The results show a similar non-conservatism in the characterisation procedure applied to the model material to that reported by Bezensek and Hancock [4] and Wilkes [5] on a mild steel at low temperatures. It is concluded that the above technique and model material accurately represent flaw characterisation under simulated cleavage conditions.
Explosive Removal of Concrete From Reinforced Walls
Authors: Rickman Denis D. , Ehrgott John Q. , Akers Stephen A. , Windham Jon E. , Moore Dennis W.
Published: August 2009

During the past several years, the US Army has focused considerable attention toward developing improved methods for breaching walls in the urban combat environment. A major thrust area is centered on finding improved methods to breach the toughest wall type that Army units are likely to face: a double (steel) reinforced concrete (RC) wall. One impediment to this effort is that the relationship between the contact explosive charge configuration and the quantity of concrete removed has not been thoroughly understood. The U.S. Army Engineer Research and Development Center has conducted a research effort to better define the effectiveness of various explosive charge configurations in breaching RC walls. This paper presents a discussion of results from this research.
The Pressure-Temperature Limit Curve of System-Integrated Modular Advanced Reactor Against Nonductile Failure
Authors: Chang Yoon-Suk , Chang Hyuk-Soo , Lee Sang-Min , Choi Jae-Boong , Kim Young-Jin , Kim Jin-Su , Chung Hae-Dong , Seul Kwang-Won
Published: August 2009

A system-integrated modular advanced reactor is being developed for multi purposes such as electricity production, sea water desalination and so on in Korea. While ASME Codes provide simplified design and operation procedures to determine allowable loadings for pressure retaining materials in components, the procedures are applicable when a temperature change rate associated with startup and shutdown is less than about 56°C/hr. If the procedures are applied to a rapid temperature change, results would be overly conservative. The objective of this research is to assess an applicability of the simplified design procedures to reactor coolant system of the integrated modular reactor with the change rates of 56°C/hr and 100°C/hr. To investigate effects of cooldown rate, heatup rate and surface crack location, systematic three-dimensional finite element analyses are carried out. The resulting pressure-temperature limit curves are compared with those obtained from the ASME Sec. XI operating procedure as well as Sec. III design procedure. Thereby, it was proven that the specific design features significantly affect the safe design region in the pressure-temperature limit curve to prevent a nonductile failure.
Analysis of thermally activated kinetics and uniformity of photoresist ashing process on 300 mm wafers
Authors: Mézerette D. L. , Tanimura K. , Vinogradov G. K.
Published: August 2009

Ashing rate and nonuniformity are the usual parameters used for the evaluation of industrial ashers. A detailed study of the wafer temperature and of its effect on the two contributions to the diminution of photoresist thickness, namely, shrinkage and chemical reactions, gives a solid ground for understanding the variations of ashing rate with process conditions. It is in particular shown how variations of shrink with temperature affect the measured ashing rate. This analysis serves as a basis for proposing tests that could be used as “standards” and ease the objective comparison of industrial ashers, based on real performances. They include a determination of ashing rate on hard-baked wafers for characterization of radical density, a demonstration of the ion-free nature of the process, and a determination of wafer heat-up rate. Due to the very reproducible nature of the distribution of ashing rates over a wafer, it is argued that the “range” parameter should be used over standard deviation for the measurement of nonuniformity within a wafer.
Mechanism of reducing line edge roughness in ArF photoresist by using CF3I plasma
Authors: Soda Eiichi , Kondo Seiichi , Saito Shuichi , Koyama Koji , Jinnai Butsurin , Samukawa Seiji
Published: August 2009

The roughening mechanism of ArF photoresist during etching was investigated to find out why CF3I gas reduces the line edge roughness (LER) in the photoresist pattern better than CF4 gas. Since the plasma of reactive ion etching (RIE) consists of ultraviolet (UV) photons, radicals, and ions, the authors used a UV lamp and a neutral beam source for evaluating the effect of different plasma compositions on the photoresist roughness. The roughness was found not to increase only by UV photons or F radicals, but increase under the CF4 RIE plasma which has both UV photons and F radicals. A C–F modified layer was generated on the resist surface because the UV damaged CO bonds reacted with F radicals and the resist surface became softer and shrank. Since CF3I plasma has a lower UV intensity and fewer F radicals compared with CF4 plasma, the shrinkage on the sidewall of the photoresist was suppressed and resulted in a smaller LER when this plasma was used.
Plasma treatment methods to improve indium bump bonding via indium oxide removal
Authors: Greer Frank , Dickie Matthew , Vasquez R. P. , Jones Todd J. , Hoenk Michael E. , Nikzad Shouleh
Published: August 2009

Flip chip hybridization, also known as bump bonding, is a packaging technique for microelectronic devices which directly connects an active element or a detector to a substrate readout face down, eliminating the need for wire bonding. Indium bump technology has been a part of hybridization for many years and has been extensively employed in the infrared imager industry. However, obtaining a reliable, high yield process for high density patterns of bumps can be quite difficult in part due to the tendency of the indium bumps to oxidize during exposure to air. In this study, plasma, thermal, and wet chemical methods were screened to determine their ability to remove indium oxide from indium bumps. A novel two-step plasma process using methane, argon, and hydrogen was developed that removes indium oxide from indium bumps after prolonged air exposure while maintaining a low sample temperature. This method was tested by fabricating a fully hybridized scientific grade visible complementary metal oxide semiconductor detector and imaging a standard test pattern.
In Vitro Activity of Colistin (Polymyxin E) against 3,480 Isolates of Gram-Negative Bacilli Obtained from Patients in Canadian Hospitals in the CANWARD Study, 2007-2008
Authors: Walkty A. , DeCorby M. , Nichol K. , Karlowsky J. A. , Hoban D. J. , Zhanel G. G.
Published: August 2009

The in vitro activity of colistin was evaluated versus 3,480 isolates of gram-negative bacilli using CLSI broth microdilution methods. The MIC
90
of colistin was ≤2 μg/ml against a variety of clinically important gram-negative bacilli, including
Escherichia coli
,
Klebsiella
spp.,
Enterobacter
spp.,
Acinetobacter baumannii
, and
Pseudomonas aeruginosa
. All multidrug-resistant (
n
= 76)
P. aeruginosa
isolates were susceptible to colistin (MIC, ≤2 μg/ml). These data support a role for colistin in the treatment of infections caused by multidrug-resistant
P. aeruginosa
.
Human Immunodeficiency Virus Type 1 Recombinant Reverse Transcriptase Enzymes Containing the G190A and Y181C Resistance Mutations Remain Sensitive to Etravirine
Authors: Xu Hongtao , Quan Yudong , Brenner Bluma G. , Bar-Magen Tamara , Oliveira Maureen , Schader Susan M. , Wainberg Mark A.
Published: August 2009

Etravirine (ETR) is a second-generation nonnucleoside reverse transcriptase (RT) inhibitor (NNRTI) active against common human immunodeficiency virus type 1 (HIV-1) drug-resistant strains. This study was designed to determine the extent to which each of the Y181C or G190A mutations in RT might confer resistance to ETR and other members of the NNRTI family of drugs. Recombinant HIV-1 RT enzymes containing either the Y181C or the G190A mutation, or both mutations in tandem, were purified. Both RNA- and DNA-dependent DNA polymerase assays were performed in order to determine the extent to which each of these mutations might confer resistance in cell-free biochemical assays against each of ETR, efavirenz, and nevirapine. Both the biochemical and the cell-based phenotypic assays confirmed the susceptibility of G190A-containing enzymes and viruses to ETR. The results of this study indicate that the G190A mutation is not associated with resistance to ETR.
Identification of a Conserved Chromosomal Region Encoding
Klebsiella pneumoniae
Type 1 and Type 3 Fimbriae and Assessment of the Role of Fimbriae in Pathogenicity
Authors: Struve Carsten , Bojer Martin , Krogfelt Karen Angeliki
Published: August 2009

Type 3 fimbriae are expressed by most clinical
Klebsiella pneumoniae
isolates and mediate adhesion to host structures in vitro. However, the role of type 3 fimbriae in
K. pneumoniae
virulence has not been evaluated by use of in vivo infection models. In this study, the type 3 fimbrial gene cluster (
mrk
) of the clinical isolate C3091 is described in detail. The
mrk
gene cluster was revealed to be localized in close proximity to the type 1 fimbrial gene cluster. Thus, a 20.4-kb fimbria-encoding region was identified and found to be highly conserved among different
K. pneumoniae
isolates. Interestingly, a homologue to PecS, known as a global regulator of virulence in
Erwinia chrysanthemi
, was identified in the fimbria-encoding region. Comparison to the previously characterized plasmid encoded
mrk
gene cluster revealed significant differences, and it is established here that the putative regulatory gene
mrkE
is not a part of the chromosomally encoded type 3 fimbrial gene cluster. To evaluate the role of type 3 fimbriae in virulence, a type 3 fimbria mutant and a type 1 and type 3 fimbria double mutant was constructed. Type 3 fimbria expression was found to strongly promote biofilm formation. However, the fimbria mutants were as effective at colonizing the intestine as the wild type, and their virulence was not attenuated in a lung infection model. Also, in a urinary tract infection model, type 3 fimbriae did not influence the virulence, whereas type 1 fimbriae were verified as an essential virulence factor. Thus, type 3 fimbriae were established not to be a virulence factor in uncomplicated
K. pneumoniae
infections. However, since type 3 fimbriae promote biofilm formation, their role in development of infections in catheterized patients needs to be elucidated.
Branched-Chain Amino Acids Are Required for the Survival and Virulence ofActinobacillus pleuropneumoniaein Swine
Authors: Subashchandrabose Sargurunathan , LeVeque Rhiannon M. , Wagner Trevor K. , Kirkwood Roy N. , Kiupel Matti , Mulks Martha H.
Published: August 2009

InActinobacillus pleuropneumoniae, which causes porcine pleuropneumonia,ilvIwas identified as an in vivo-induced (ivi) gene and encodes the enzyme acetohydroxyacid synthase (AHAS) required for branched-chain amino acid (BCAA) biosynthesis.ilvIand 7 of 32 additionalivipromoters were upregulated in vitro when grown in chemically defined medium (CDM) lacking BCAA. Based on these observations, we hypothesized that BCAA would be found at limiting concentrations in pulmonary secretions and thatA. pleuropneumoniaemutants unable to synthesize BCAA would be attenuated in a porcine infection model. Quantitation of free amino acids in porcine pulmonary epithelial lining fluid showed concentrations of BCAA ranging from 8 to 30 μmol/liter, which is 10 to 17% of the concentration in plasma. The expression of bothilvIandlrp, a global regulator that is required forilvIexpression, was strongly upregulated in CDM containing concentrations of BCAA similar to those found in pulmonary secretions. Deletion-disruption mutants ofilvIandlrpwere both auxotrophic for BCAA in CDM and attenuated compared to wild-typeA. pleuropneumoniaein competitive index experiments in a pig infection model. Wild-typeA. pleuropneumoniaegrew in CDM+BCAA but not in CDM−BCAA in the presence of sulfonylurea AHAS inhibitors. These results clearly demonstrate that BCAA availability is limited in the lungs and support the hypothesis thatA. pleuropneumoniae, and potentially other pulmonary pathogens, uses limitation of BCAA as a cue to regulate the expression of genes required for survival and virulence. These results further suggest a potential role for AHAS inhibitors as antimicrobial agents against pulmonary pathogens.
Secondhand tobacco smoke concentrations in motor vehicles: a pilot study
Authors: Jones M R , Navas-Acien A , Yuan J , Breysse P N
Published: August 2009

Context:

Motor vehicles represent important microenvironments for exposure to secondhand smoke (SHS). While some countries and cities have banned smoking in cars with children present, more data are needed to develop the evidence base on SHS exposure levels in motor vehicles to inform policy and education practices aimed at supporting smoke-free motor vehicles when passengers are present.

Objective:

To assess exposure to secondhand tobacco smoke in motor vehicles using passive airborne nicotine samplers.

Methods:

17 smokers and five non-smokers who commute to and from work in their own vehicle participated. Two passive airborne nicotine samplers were placed in each vehicle for a 24-hour period, one at the front passenger seat headrest and the other in the back seat behind the driver. At the end of the sampling period, airborne nicotine was analysed by gas chromatography.

Results:

Median (IQR) air nicotine concentrations in smokers’ vehicles were 9.6 μg/m3(5.3–25.5) compared to non-detectable concentrations in non-smokers’ vehicles. After adjustment for vehicle size, window opening, air conditioning and sampling time, there was a 1.96-fold increase (95% CI 1.43 to 2.67) in air nicotine concentrations per cigarette smoked.

Conclusions:

Air nicotine concentrations in motor vehicles were much higher than air nicotine concentrations generally measured in public or private indoor places, and even higher than concentrations measured in restaurants and bars. These high levels of exposure to SHS support the need for education measures and legislation that regulate smoking in motor vehicles when passengers, especially children, are present.
GENERAL EIGENVALUE PROBLEMS WITH UNBOUNDED POTENTIAL FROM BELOW
Authors: SOUS A. J. , EL-KAWNI M. I.
Published: August 2009

The eigenvalues of unbounded potential from below of the form [Formula: see text], has been obtained over a full range of the parameter values a and b. The calculated results are in complete agreement with exact numerical results obtained by H.-T. Cho and C.-L. Ho. Moreover, we also obtained analytical expression for En in the case when b = 0. Some new results for non-quasiexactly solvable case are presented using the asymptotic iteration method.
P-WAVE MESON SPECTRUM IN A RELATIVISTIC MODEL WITH INSTANTON INDUCED INTERACTION
Authors: VIJAYA KUMAR K. B. , BHAVYASHRI  , MA YONG-LIANG , MONTEIRO ANTONY PRAKASH
Published: August 2009

On the basis of the phenomenological relativistic harmonic models for quarks, we have obtained the masses of P-wave mesons. The full Hamiltonian used in the investigation has Lorentz scalar + vector confinement potential, along with one-gluon-exchange potential (OGEP) and the instanton-induced quark–antiquark interaction (III). A good agreement is obtained with the experimental masses. The respective role of III and OGEP for the determination of the meson masses is discussed.
INVESTIGATING AdS/QCD DUALITY THROUGH THE SCALAR GLUEBALL CORRELATOR
Authors: COLANGELO P. , DE FAZIO F. , JUGEAU F. , NICOTRI S.
Published: August 2009

We investigate AdS/QCD duality for the two-point correlation function of the lowest dimension scalar glueball operator, in the case of the IR soft wall model. We point out the role of the boundary conditions for the bulk-to-boundary propagator in determining the gluon condensates. We show how a low energy QCD theorem can be obtained within the AdS approach, together with a gluon condensate close to the commonly accepted value and robust against perturbation of the background dilaton field.
FINITE ELEMENT METHODS FOR STRUCTURAL ACOUSTICS ON MISMATCHED MESHES
Authors: WALSH TIMOTHY , REESE GARTH , DOHRMANN CLARK , ROUSE JERRY
Published: August 2009

In this paper, a new technique is presented for structural acoustic analysis in the case of nonconforming acoustic–solid interface meshes. We first describe a simple method for coupling nonconforming acoustic–acoustic meshes, and then show that a similar approach, together with the coupling operators from conforming analysis, can also be applied to nonconforming structural acoustics. In the case of acoustic–acoustic interfaces, the continuity of acoustic pressure is enforced with a set of linear constraint equations. For structural acoustic interfaces, the same set of linear constraints is used, in conjunction with the weak formulation and the coupling operators that are commonly used in conforming structural acoustics. The constraint equations are subsequently eliminated using a static condensation procedure. We show that our method is equally applicable to time domain, frequency domain, and coupled eigenvalue analysis for structural acoustics. Numerical examples in both the time and frequency domains are presented to verify the methods.
NEAR-SURFACE LOCALIZATION AND SHAPE IDENTIFICATION OF A SCATTERER EMBEDDED IN A HALFPLANE USING SCALAR WAVES
Authors: JEONG CHANSEOK , NA SEONG-WON , KALLIVOKAS LOUKAS F.
Published: August 2009

We discuss the inverse problem associated with the identification of the location and shape of a scatterer fully embedded in a homogeneous halfplane, using scant surficial measurements of its response to probing scalar waves. The typical applications arise in soils under shear (SH) waves (antiplane motion), or in acoustic fluids under pressure waves. Accordingly, we use measurements of either the Dirichlet-type (displacements), or of the Neumann-type (fluid velocities), to steer the localization and detection processes, targeting rigid and sound-hard objects, respectively. The computational approach for localizing single targets is based on partial-differential-equation-constrained optimization ideas, extending our recent work from the full-1 to the half-plane case. To improve on the ability of the optimizer to converge to the true shape and location we employ an amplitude-based misfit functional, and embed the inversion process within a frequency- and directionality-continuation scheme, which seem to alleviate solution multiplicity. We use the apparatus of total differentiation to resolve the target's evolving shape during inversion iterations over the shape parameters, à la.2,3 We report numerical results betraying algorithmic robustness for both the SH and acoustic cases, and for a variety of targets, ranging from circular and elliptical, to potato-, and kite-shaped scatterers.
SEMI-CLASSICAL STATES FOR QUASILINEAR SCHRÖDINGER EQUATIONS ARISING IN PLASMA PHYSICS
Authors: DO Ó JOÃO MARCOS , MOAMENI ABBAS , SEVERO UBERLANDIO
Published: August 2009

In this paper, the existence and qualitative properties of positive ground state solutions for the following class of Schrödinger equations -ε2Δu + V(x)u - ε2[Δ(u2)]u = f(u) in the whole two-dimensional space are established. We develop a variational method based on a penalization technique and Trudinger–Moser inequality, in a nonstandard Orlicz space context, to build up a one parameter family of classical ground state solutions which concentrates, as the parameter approaches zero, around some point at which the solutions will be localized. The main feature of this paper is that the nonlinearity f is allowed to enjoy the critical exponential growth and also the presence of the second order nonhomogeneous term -ε2[Δ(u2)]u which prevents us from working in a classical Sobolev space. Our analysis shows the importance of the role played by the parameter ε for which is motivated by mathematical models in physics. Schrödinger equations of this type have been studied as models of several physical phenomena. The nonlinearity here corresponds to the superfluid film equation in plasma physics.
SCATTERING THEORY FOR THE GROSS–PITAEVSKII EQUATION IN THREE DIMENSIONS
Authors: GUSTAFSON STEPHEN , NAKANISHI KENJI , TSAI TAI-PENG
Published: August 2009

We study the global behavior of small solutions of the Gross–Pitaevskii equation in three dimensions. We prove that disturbances from the constant equilibrium with small, localized energy, disperse for large time, according to the linearized equation. Translated to the defocusing nonlinear Schrödinger equation, this implies asymptotic stability of all plane wave solutions for such disturbances. We also prove that every linearized solution with finite energy has a nonlinear solution which is asymptotic to it. The key ingredients are: (1) some quadratic transforms of the solutions, which effectively linearize the nonlinear energy space, (2) a bilinear Fourier multiplier estimate, which allows irregular denominators due to a degenerate non-resonance property of the quadratic interactions, and (3) geometric investigation of the degeneracy in the Fourier space to minimize its influence.
FINITE-DIMENSIONAL SPECIAL ODD HAMILTONIAN SUPERALGEBRAS IN PRIME CHARACTERISTIC
Authors: LIU WENDE , HE YINGHUA
Published: August 2009

In this paper, we study a new family of finite-dimensional simple Lie superalgebras of Cartan type over a field of characteristic p > 3, the so-called special odd Hamiltonian superalgebras. The spanning sets are first given and then the grading structures are described explicitly. Finally, the simplicity and the dimension formulas are determined. As application, using the dimension formulas, we make a comparison between the special odd Hamiltonian superalgebras and the other known families of finite-dimensional simple modular Lie superalgebras of Cartan type.
NEW METHOD OF NEURON DESIGN BASED ON DISCRETE Z-FUNCTION TO ADAPT THE CHANGE OF INTEGRATED VEHICLE STABILITY CONTROL ORDER
Authors: HARLY M. , SUTANTRA I. N. , MAURIDHI H. P.
Published: August 2009

Fixed order neural networks (FONN), such as high order neural network (HONN), in which its architecture is developed from zero order of activation function and joint weight, regulates only the number of weight and their value. As a result, this network only produces a fixed order model or control level. These obstacles, which affect preceeding architectures, have been performing finite ability to adapt uncertainty character of real world plant, such as driving dynamics and its desired control performance.

This paper introduces a new concept of neural network neuron. In this matter, exploiting discrete z-function builds new neuron activation. Instead of zero order joint weight matrices, the discrete z-function weight matrix will be provided to realize uncertainty or undetermined real word plant and desired adaptive control system that their order has probably been changing. Instead of using bias, an initial condition value is developed. Neural networks using new neurons is called Varied Order Neural Network (VONN). For optimization process, updating order, coefficient and initial value of node activation function uses GA; while updating joint weight, it applies both back propagation (combined LSE-gauss Newton) and NPSO. To estimate the number of hidden layer, constructive back propagation (CBP) was also applied.

Thorough simulation was conducted to compare the control performance between FONN and MONN. In order to control, vehicle stability was equipped by electronics stability program (ESP), electronics four wheel steering (4-EWS), and active suspension (AS). 2000, 4000, 6000, 8000 data that are from TODS, a hidden layer, 3 input nodes, 3 output nodes were provided to train and test the network of both the uncertainty model and its adaptive control system.

The result of simulation, therefore, shows that stability parameter such as yaw rate error, vehicle side slip error, and rolling angle error produces better performance control in the form of smaller performance index using FDNN than those using MONN.
The financial meltdown and computing
Authors: Vardi Moshe Y.
Published: August 2009

For many of us, the past year has been one of the most unsettling in our lifetime. In the late 1980s and early 1990s, we watched communism collapse of its own dead weight. In late 2008, we saw capitalism nearly crumble. Lehman Brothers, a major U.S. investment bank, declared bankruptcy last September, sending the world's financial system into a tailspin. Only a massive intervention by central banks saved the system from collapse.
Saying good-bye to DBMSs, designing effective interfaces
Authors: Stonebraker Michael , Hong Jason
Published: August 2009

The
Communications
Web site, http://cacm.acm.org, features 13 bloggers in the BLOG@CACM community. In each issue of
Communications
, we'll publish excerpts from selected posts, plus readers' comments.

Michael Stonebraker discusses the problems with relational database management systems and possible solutions, and Jason Hong writes about interfaces and usable privacy and security.
Medical nanobots
Authors: Kroeker Kirk L.
Published: August 2009

Researchers working in medical nanorobotics are creating technologies that could lead to novel health-care applications, such as new ways of accessing areas of the human body that would otherwise be unreachable without invasive surgery.
Facing an age-old problem
Authors: Greengard Samuel
Published: August 2009

Researchers are addressing the computing challenges of older individuals, whose needs are different---and too often disregarded.
Law and technologyKeeping track of telecommunications surveillance
Authors: Schwartz Paul M.
Published: August 2009

The creation of a statistical index of U.S. telecommunications surveillance activities and their results will benefit both civil liberties and law enforcement.
Sound index
Authors: Bhagwan Varun , Grandison Tyrone , Gruhl Daniel
Published: August 2009

Mining the wisdom of the online crowds generates music business intelligence, identifying what's hot and what's not.
Examining user involvement in continuous software development
Authors: Muthitacharoen Achita (Mi) , Saeed Khawaja A.
Published: August 2009

Ms. Perez was giving a powerpoint presentation to her potential clients in the hope of landing a big contract. She was presenting a new advertising campaign for a mutual fund company and had spent three months with her team on perfecting the proposal. Everything seemed to be going well when suddenly a small window screen popped up informing her that an error had occurred and asked if she would wish to send an error report. She clicked the send button and the application on her laptop shut down, disrupting the flow of her presentation and making her look unprofessional.

This story entails an example of a user's experience and response to a new method for collecting information on software application errors. To maintain a certain level of quality and ensure customer satisfaction, software firms spend approximately 50% to 75% of the total software development cost on debugging, testing, and verification activities. Despite such efforts, it is not uncommon for a software application to contain errors after the final version is released. To better manage the software development process in the long run firms are involving the users in software improvement initiatives by soliciting error information, while they are using the software application. The information collected through an error reporting system (ERS) plays an important role in uncovering bugs and prioritizing future development work. Considering that about 20% of bugs cause 80% of the errors, gathering information on application errors can substantially improve software firms' productivity and improve the quality of their products. High quality software applications can benefit the software users individually and also help improve the image of the software community as a whole. Thus, understanding the emerging error reporting systems (ERS) and why users adopt them are important issues that require examination. Such an analysis can help the software companies in learning how to design better ERS and educate the users about ERS and its utilities.
Overcoming the insider
Authors: Willison Robert , Siponen Mikko
Published: August 2009

Information security has become increasingly important for organizations, given their dependence on ICT. Not surprisingly, therefore, the external threats posed by hackers and viruses have received extensive coverage in the mass media. Yet numerous security surveys also point to the 'insider' threat of employee computer crime. In 2006, for example, the Global Security Survey by Deloitte reports that 28% of respondent organizations encountered considerable internal computer fraud. This figure may not appear high, but the impact of crime perpetrated by insiders can be profound. Donn Parker argues that 'cyber-criminals' should be considered in terms of their criminal attributes, which include skills, knowledge, resources, access and motives (SKRAM). It is as a consequence of such attributes, acquired within the organization, that employers can pose a major threat. Hence, employees use skills gained through their legitimate work duties for illegitimate gain. A knowledge of security vulnerabilities can be exploited, utilising resources and access are provided by companies. It may even be the case that the motive is created by the organization in the form of employee disgruntlement. These criminal attributes aid offenders in the pursuit of their criminal acts, which in the extreme can bring down an organization.

In the main, companies have addressed the insider threat through a workforce, which is made aware of its information security responsibilities and acts accordingly. Thus, security policies and complementary education and awareness programmes are now commonplace for organizations. That said, little progress has been made in understanding the insider threat from an offender's perspective. As organizations attempt to grapple with the behavior of dishonest employees, criminology potentially offers a body of knowledge for addressing this problem. It is suggested that Situational Crime Prevention (SCP), a relative newcomer to criminology, can help enhance initiatives aimed at addressing the insider threat.

In this article, we discuss how recent criminological developments that focus on the criminal act, represent a departure from traditional criminology, which examines the causes of criminality. As part of these recent developments we discuss SCP. After defining this approach, we illustrate how it can inform and enhance information security practices.

In recent years, a number of criminologists have criticised their discipline for assuming that the task of explaining the causes of criminality is the same as explaining the criminal act. Simply to explain how people develop a criminal disposition is only half the equation. What is also required is an explanation of how crimes are perpetrated. Criminological approaches, which focus on the criminal act, would appear to offer more to information security practitioners than their dispositional counterparts. Accordingly, the SCP approach can offer additional tools for practitioners in their fight against insider computer crime.
Modified agile practices for outsourced software projects
Authors: Batra Dinesh
Published: August 2009

Frustration with the bureaucratic nature of the disciplined approach has led to the call for agile development. The new approach is defined by the Agile Manifesto (http://agilemanifesto.org/), which values individuals and interactions over processes and tools, working software over comprehensive documentation, customer collaboration over contract negotiation, and agility in responding to change over following a prescribed plan. Agile development does not focus on process improvement; instead it focuses on customer satisfaction and employee empowerment. This is evident from reading the stated values and principles of the Agile Manifesto, which include fairly extreme positions such as "welcome changing requirements, even late in development" and "the best architectures, requirements, and designs emerge from self-organizing teams."

An interesting issue arising from the call for agile development is its role in distributed development, which usually translates to offshore development. A recent study indicates that agile practices can reduce temporal, geographical, and socio-cultural distances in distributed development projects. The study researched agile development between teams located in the U.S. and Ireland, and while it reported that overall communication was improved, it also noted problems related to geographical, temporal, and even language distances. Although there are other reported successes of distributed agile development, the projects are generally small, the team members are likely familiar with each other, and the participants are largely experts or high caliber developers.

This raises a research, as well as a practical, question: can we extend the use of agile practices from small projects to medium and large projects that involve a significant outsourcing component? To address this question, we must drop constraints such as small size projects, and expert developers belonging to the same company, and examine problems arising from geographical, temporal, and cultural distances. Accordingly, agile practices may need to be modified.

In this article, the key issues of software projects with an outsourced component are first identified. These issues are then used as a background to evaluate how standard agile practices stand up when applied to larger projects. This evaluation is followed by recommendations for modified agile practices for outsourced software projects.