bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Gribov Process: Soft Parton Interactions in So‐Called Reggeon Field Theory
Authors: Grassberger P. 
Published: July 2007

AbstractAs shown in previous papers, Reggeon “Field” Theory is actually a Markov process describing the evolution of wee partons during a boost. In the present paper, the physical interpretation of scattering amplitudes and cross sections is discussed, both for the uncut (unlabelled) and cut (labelled) version. Elastic amplitudes and total cross sections, inclusive cross sections, fully diffractive events, and inelastic diffraction are all shown to have simple interpretations in the parton model. Finally, the connection with models for evolution of hard partons in QCD is discussed.
Quantum Chromodynamics and Parity‐Violating Nucleon‐Nucleon‐Pion Coupling
Authors: Galić Harvoje , Guberina Branko , Tadić Dubravko 
Published: July 2007

AbstractParity‐violating (PV) nucleon‐nucleon‐pion (NNπ) coupling is studied in order to extract information about nonleptonic weak processes in general. The connection between the PV NNπ amplitude and PV nonleptonic hyperon decays is explored in detail. An outline of the historical background is given. It is shown how the PV NNπ amplitude is to be calculated starting from the Weinberg‐Salam model for weak interactions. The effective weak Hamiltonian for PV nonleptonic processes is derived in detail, introducing quantum chromodynamics and flavor‐symmetry breaking. The role of the so‐called penguin terms is clarified. The PV NNπ amplitude is calculated using current algebra, chiral invariance, and quark models (e.g. the MIT bag model) for the description of baryons. It is emphasized that certain techniques used in the description of nonleptonic decays can undergo an independent test via the study of PV NNπ amplitudes. These amplitudes can be experimentally explored in experiments on nuclear parity violation. A discussion of nuclear calculations and experiments is also included.
Perturbation Theory, Level‐Splitting and Large‐Order Behaviour
Authors: Müller‐Kirsten H. J. W. 
Published: July 2007

AbstractThe level‐splitting of asymptotically degenerate eigenvalues, their discontinuity across a cut and the large‐order behaviour of the perturbation expansion are usually difficult to calculate. In the following we review some methods of calculation with particular emphasis on the periodic potential in order to exhibit the relationship between all three quantities.
Phenomenology of Elastic Hadron Diffraction
Authors: Jenkovszky L. L. 
Published: July 2007

AbstractRecent experimental data on high‐energy elastic scattering of hadrons is reviewed in the light of various theoretical models with special emphasize on the dipole (or geometrical) Pomeron. As suggested by its name, this model combines the properties of two different approaches: the analytic and geometric ones. Its virtue is simplicity, which makes possible analytic calculation of many complicated problems.
What happened to the system perspective in reliability?
Authors: Halverson M. , Ozdes D. 
Published: July 2007

AbstractThis paper takes a broad overview of the reliability and safety engineering practice as it is commonly exercised in the aerospace and military industries today, especially with respect to complex electronic equipment which typically includes considerable software content. A general deficiency is noted with regard to the system‐level approach to reliability. It would appear that the system‐level reliability activities are given less attention than is needed, while excessive emphasis is placed on component micro‐physics, component failure models, and various component‐oriented analyses. Systems‐level reliability topics, which predominate in the equipment reliability which is actually observed, are sometimes ignored by reliability engineers.Methods and practical philosophies to re‐establish a solid system engineering foundation for contemporary reliability practice, which have been developed through the authors' experience in the field, are presented. Finally, an example analysis is shown to illustrate the concepts.
Quality and reliability assessment of hardware and software during the total product life cycle
Authors: Jones David R. , Murthy Vyasaraj , Blanchard Jeffrey 
Published: July 2007

AbstractA major challenge for the computer industry is the need for the development and implementation of an engineering languge which provides continuous linkages and measurement between the customer and all engineering functions internal to the company. Such a language would allow information solution developers and information service providers to be able to continuously monitor the quality and reliability performance of integrated hardware and software products during the complete product life cycle. A quantitative engineering language needs to be developed to provide seamless and continuous linkages between the customer—the user of integrated computer systems—and all of the engineering development and manufacturing functions tasked with designing and building solutions which meet customer needs. A methodology is proposed which addresses this challenge by the implementation of two metrics: total defects per unit (TDU) and the annual rate of events (ARE). These two metrics can measure all hardware, software and computer integration events during the total product life cycle. A methodology is presented which provides a rigorous translation of the ARE metric, monitored at the customer site, into the traditional reliability metrics used by engineering and manufacturing. Algorithms are presented which directly translate AREs into mean time between failures (MTBF), mean time between parts replacement (MTBPR) and mean time between system interruptions (MTBSI). The ARE metric meets the customer requirement of being able to clearly focus on the reliability and availability performance of total systems as a result of hardware and software components, the user interface, and environmental factors. The paper discusses the development and application of integrated TDU and ARE metrics and shows how the total product life cycle quality and reliability of a complex integrated computer and communications solution can be efficiently monitored and managed for improvement during design, manufacturing, and installation performance in an integrated customer environment.
Simulation strategies to identify the failure parameters of repairable systems under the influence of general repair
Authors: Love C. E. , Guo R. 
Published: July 2007

AbstractWith repairable systems, it is suspected than many of the post‐failure repairs have the effect of partially resetting the failure rate of the system. Consequently, identifying the correct failure model and its associated parameters is confounded by the impact of these repair effects. The purpose of this paper is to compare the use of several simulation strategies involving mimicking experiments, to assist in this identification process. Data collected from a hydrelectric turbine unit is used to illustrate the approach.
Lifetime test evaluation with mathcad®: Automated weibull parameter and plotting point estimate with arbitrary confidence interval and graphics
Authors: Accumolli Alberto , Sjöberg Sven 
Published: July 2007

AbstractThis application note describes a computer‐based method for automated evaluation of Weibull‐distributed life‐time data. It uses comercially available software, MathCad, to set up equations and graphs. The computer application is a simple and non‐expensive way of evaluating and displaying your life‐time data taking into consideration both parametric and non‐parametric confidence intervals. It is valid for arbitrarily censored data.
Modelling rail vehicle brake pad wearout and replacement
Authors: Bohoris G. A. , Desai A. , Edge D. J. 
Published: July 2007

AbstractInspections of rail vehicle multiple units are scheduled in British Rail mainly subject to the recommended interval between inspections of brake pads. This paper presents the development of a model of brake pad wear based on regression analysis and its subsequent use in the consideration of replacement and inspection strategies. The current scrapping size of 11 mm on motor vehicles proved to be too high for it was possible to extend pad life by as much as a third by reducing the scrapping size to 7 mm. On trailer vehicles it was found that the current scrapping size of 6 mm was satisfactory.
Efficient distributed algorithm to solve updating minimum spanning tree problem
Authors: Park Jungho , Hagihara Ken'Ichi , Tokura Nobuki , Masuzawa Toshimitsu 
Published: July 2007

AbstractThis paper proposes a distributed algorithm for reconstructing a minimum‐weight spanning tree T′ of a network N′ when link addition and deletion occur in a network N with a minimum‐weight spanning tree T. In this algorithm each processor uses information whose adjacent links belong to T in order to construct T′ efficiently. The communication complexity and ideal time complexity of the algorithm are O(n log(f + t) + m) and O(n log(f + t) + n), respectively, where n and e are the number of processors and that of links in N′, t is the number of added links, and f represents that of deleted links belonging to T. Here, m = n + t when f = 0 and m = e otherwise.This paper also presents a distributed algorithm for reconstructing a minimum‐weight spanning tree T+ when links and processors are added and deleted. The communication complexity and ideal time complexity of the algorithm are O(n log(g + h) + r and O(n log(g + h) + n), respectively, where g is the total number of added links (including links incident to added processors) and h represents the number of deleted links belonging to T (including links incident to deleted processors). Thus, r = n + g when h = 0 and r = e when h > 0.
RMD‐tree: A hierarchical data structure for multidimensional nonzero size spatial objects using MD‐tree
Authors: Nakamura Yasuaki , Abe Shigeru , Ohsawa Yutaka , Sakauchi Masao 
Published: July 2007

AbstractThis paper proposes an RMD‐tree (region multidimensional tree), which is a method of data management based on the tree structure, aiming at the efficient management and retrieval of spatial objects with nonzero sizes.In the proposed method, the spatial object in the N‐dimensional space corresponds to a point in the 2N‐dimensional space, being represented by its centroid and the extent along each axis. The coordinate transformation is applied to the point data and the data are managed by the tree structure, so that retrieval such as the point location problem or the range search in the n‐dimensional space can be performed only by the search for the point data in the hyper‐rectangle range.By this approach, the space splitting and data management are made possible considering the size of the object as well as the centroid. By the coordinate transformation the object data are represented by the maximum and the minimum in the original N‐dimensional space, multiplied by a certain factor.It is indicated by simulation experiments that the speed of search is improved by this method by a factor of 2 to 4, compared to the conventional method when the size of the object to be managed is enlarged. When points and objects with small sizes are to be handled, the performance is almost the same as that of the conventional method. In the experiment using the actual printed circuit board data, the speed of search also is improved by approximately a factor of 2.
Distributed algorithms for connectivity problem of networks with faulty elements
Authors: Wada Koichi , Moritani Yukio , Kawaguchi Kimio , Morishita Masahiro 
Published: July 2007

AbstractDistributed algorithms for computing the connectivity of an asynchronous computer network with faulty computers and links are investigated. Computers which are adjacent to faulty computers and links are assumed to be capable of detecting the faults. The existence and efficiency of distributed algorithms depend on the kinds of information each computer is allowed to have on the network before executing an algorithm.Here, the case in which computers fail and the case in which only links fail are considered separately. It is shown that in the former case there is no algorithm for computing the connectivity regardless of the kind of information a computer has about the network. In the latter case the existence of a distributed algorithm, upper and lower bounds of communication complexity and ideal time complexity are discussed for the following three cases: each computer has only the basic information (its identifier and the number of links connected to it); each computer has the basic information and the identifier of the adjacent computers; and each computer has the basic information and the size of the network.
Implementation of the prodigy parallel AI machine and performance evaluation of communication
Authors: Tanabe Noboru , Nakamura Sadao , Suzuoka Takashi , Oyanagi Shigeru 
Published: July 2007

AbstractAt present, the binary n‐cube is considered to be interesting as an interconnection network for the highly parallel computers. Most of those networks, however, use the serial communication channel, which prevents the realization of satisfactory communication performance. From such a viewpoint, it is desired to construct an interconnection network with higher speed, higher versatility, and the easy implementation.The authors have already proposed the base‐m n‐cube as the interconnection network for the parallel AI machine Prodigy. This paper shows that the base‐m n‐cube is better than the binary n‐cube in versatility and easy implementation. Furthermore, the authors developed Prodigy which utilizes the forementioned excellent property to connect 512 processors by the 8‐bit width full duplex base‐8 3‐cube with a handshake. Two kinds of gate arrays are used in the implementation. It is shown as a result that the interconnection network can be constructed with the highest speed in the presently known cube‐type highly parallel computers. It is verified by an actual measurement that the transfer performance is deteriorated only slightly by the collision in the random communication.
Component‐based protocol synthesis
Authors: Kakuda Yoshiaki , Wakahara Yasushi , Saito Hironori 
Published: July 2007

AbstractProtocol synthesis is a very important technology for efficiently designing correct protocol specifications. One powerful means of protocol synthesis is the completion of protocol specifications which, based on a partial specification of functionally incomplete protocol, automatically generates the insufficient part. In contrast to such protocol synthesis, this paper proposes a method for completing protocol specifications with two processes by modeling the protocol by a finite‐state machine and combining fundamental components of correct protocol.Compared to conventional method, the protocol synthesis method proposed in this paper has the following merits: (1)protocols containing looping receive‐transition sequences can be generated; and (2)redundant send‐transition sequences can be eliminated. Because of these merits, it is possible to synthesize protocols used in actual communication systems, for example, the X.25 call setup/clearing protocol.
A scan conversion algorithm using quad‐tree representation of dZ buffer
Authors: Yamamoto Tsuyoshi 
Published: July 2007

AbstractThis paper proposes an extension of the Z buffer or dZ buffer that stores not only the Z component but also the normal vector of a visible polygon at the sampling point. While the conventional Z buffer algorithm is based on a zeroth‐order approximation of a visible polygon, the dZ buffer is considered as a first‐order approximation. As a result, the dZ buffer can approximate a surface by fewer sampling points.A quad‐tree based internal representation of the dZ buffer and scan conversion algorithm has been proposed using the representation. The proposed algorithm uses memory in proportion to the complexity of the generated image while the Z buffer uses memory in proportion to the image size. While the algorithm allows an incremental update of the dZ buffer as similarly to the Z buffer, anti‐alias processing is possible by controlling oversampling on demand.The algorithm can be implemented using recursive procedure calls including simple overlapping detection of triangles and rectangles. The algorithm is implemented and evaluated on a UNIX workstation and the result shows better figures in both conversion time and memory requirement.
A SYSTEMS APPROACH TO THE MANAGEMENT OF DRUG‐RELATED PROBLEMS
Authors: REILLY D.K. , HEGG J. , TWYMAN D. 
Published: July 2007

ABSTRACTA comprehensive assessment of an individual's drug problem needs to include consideration of the type, frequency and amount of drug use, degree of dependence, concomitant medical problems and general health, previous treatment history, family and social relationships, employment and financial situation, psychological functioning, criminal activity and legal situation. The aim of a community based drug advisory service in Sydney is to provide an assessment‐referral‐treatment service which aims to match an individual's drug‐related problems to the most appropriate range of therapeutic interventions. The components of the system include: intake, assessment, case conference, intervention and research. The system also accommodates the NSW Drug and Alcohol Court Assessment Program which interfaces Criminal Justice and Health Systems. Clinical programs of the service are described including a methadone maintenance program.
Glucocorticoids Inhibit the Cerebral Microvascular Dysfunction Associated with Sepsis in Obese Mice
Authors: VACHHARAJANI VIDULA , VITAL SHANTEL , RUSSELL JANICE , SCOTT L. Keith , GRANGER D. Neil 
Published: July 2007

ABSTRACTObjectives: Obesity is associated with increased morbidity and mortality in critically ill patients. It is unclear whether this increase is due to exaggerated inflammatory response alone or due to lack of response to therapeutic agents used. The objective of this study was to determine whether low‐dose steroid therapy, which has proven effective in clinical setting, affords any benefit in the increased morbidity to sepsis in genetically obese (ob/ob) mice.Methods: Intravital videomicroscopy was used to monitor and quantify the adhesion of platelets and leukocytes in the brain microcirculation of lean (WT) and ob/ob mice subjected to cecal ligation and puncture (CLP) with or without dexamethasone 4 mg/kg within 15 min of surgery. The dual radiolabeled monoclonal antibody method was used to measure P‐selectin expression in the microcirculation, while the sepsis‐induced behavioral deficit was quantified using a multicompartment chamber test.Results: Dexamethasone completely prevented the accumulation of adherent leukocytes and platelets observed at 4 h after CLP in both WT and ob/ob mice. The steroid also prevented the CLP‐induced upregulation of P‐selectin in the brain and other vascular beds, and it attenuated the behavioral deficit in ob/ob, but not in lean, mice.Conclusion: Low‐dose glucocorticoid therapy is beneficial in experimental sepsis in obese animals compared to lean animals.
Vitamin E protects the brain against oxidative injury stimulated by excessive aluminum intake
Authors: El‐Fattah Amal A. Abd , Al‐Yousef Hanan M. , Al‐Bekairi Abdullah M. , Al‐Sawaf Hussein A. 
Published: July 2007

AbstractThe effect of feeding groups of mice with a diet containing 2000, 4000 and 6000 μg aluminum (Al3+/g) for two weeks (subacute) or 2000 and 4000 μg Al3+/g for eight weeks (subchronic) as well as the coadministration of vitamin E (α‐tocopherol) 500 μg/g with Al3+, on the status of glutathione (GSH) and lipid peroxides as thiobarbituric acid reactive substances (TBARS) in whole brain tissues were evaluated. Changes in TBARS were further evaluated in vitro following the incubation of brain homogenates of the Al3+‐fed mice in the presence of 50 μM FeSO4. The results of subacute experiments revealed that the brain levels of GSH were significantly decreased only in the group of mice that received 6000 μg Al3+/g diet (P<0.05) and this effect was partially ameliorated when vitamin E was coadministered with Al3+. TBARS were significantly increased in vitro only in the presence of free iron ions and depended on the concentration of Al3+ in the diet. The effect was opposed by the vitamin E intake.Following subchronic Al3+ intake, the GSH content of the brain was significantly decreased only in the group of mice that received 4000 μg Al3+/g diet (P<0.01), while TBARS were significantly increased in the brain tissues in vivo as well as in the presence of free iron ions in vitro. However, coadminstration of vitamin E with Al3+ for eight weeks preserved GSH levels and decreased TBARS in the brain of mice in vivo and in the presence of free iron ions in vitro. It is concluded that the long term administration of vitamin E may prevent Al3+‐stimulated oxidative injury in the brain.
CYP2B2 gene expression and phenobarbital induction in kidneys using an in vitro transcription system
Authors: Shervington Amal 
Published: July 2007

AbstractThe induction of cytochrome P450 2B1 and 2B2 in rat liver in response to phenobarbital is mediated at the transcriptional level. While in extrahepatic tissue such as the kidney, the transcription level of the CYP 2B2 gene is much lower than in the liver. The transcriptional activity of the CYP2B2 promoter constructs in nuclear proteins from kidney revealed that the in vitro system maintained the tissue‐specificity of CYP2B2 transcriptional induction but not that of the basal transcription of the gene.
Purification of cytochrome P‐450 from pig testis by aniline‐sepharose 4B and isoelectric focusing
Authors: Kuwada Masahiro , Furuse Yuko , Hasumi Hideo , Maki Jun 
Published: July 2007

AbstractTesticular cytochrome P‐450 was purified by a procedure including preparative isoelectrofocusing. The cytochrome P‐450 was detemained to have an isoelectric point of 6.47 on analytical isoelecfric focusing. The purified cytochrome P‐450 was found to be homogeneous and its molecular weight was estimated to be 52000 on polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. The carbon monoxide difference spectrum with a peak at 448 nm exhibited absorption spectrum of a typical cytochrome P‐450. 284‐fold purification was achieved with an yield of 10.6 %. Following preparation of the microsomes, the purification is accomplished by a two‐step procedure utilizing Aniline‐Sepharose 4B column chromatography and preparative isoelectric focusing.
Lysosomal glycerophosphocholine phosphodiesterase in Tetrahymena
Authors: Florin‐Christensen J. , Florin‐Christensen M. 
Published: July 2007

AbstractThe purification and characterization of a novel phosphodiesterase (PDE) is presented. The activity was detected in the extracellular medium of Tetrahymena thermophila cultures, by the release of p‐nitrophenol from p‐nitrophenylphosphocholine (PNPPC) with an acidic pH optimum: In cell homogenates, it is sedimentable, shows a latency similar to that of acid phosphatase and is co‐secreted with this enzyme, indicating that it is a lysosomal hydrolase. PNPPC‐PDE was purified to homogeneity from the extracellular medium, yielding a single band of 58 kD on SDS polyacrylamide gel electrophoresis. It catalyzed the release of glycerol from glycerophosphocholine (GPC) and GPC competitively inhibits degradation of PNPPC. We present further evidence indicating that the natural substrate for PNPPC‐PDE is GPC. Thus, Tetrahymena becomes the first eukaryote in which a lysosomal GPC‐PDE is observed. This finding provides a new pathway for the complete breakdown of phosphatidylcholine in a lysosomal medium.