Home About us Contact
|
Home About us Contact | ||
|
|
||
System Analysis (system + analysis)
Selected AbstractsMeasurement System Analysis for Bounded Ordinal DataQUALITY AND RELIABILITY ENGINEERING INTERNATIONAL, Issue 5 2004Jeroen de Mast Abstract The precision of a measurement system is the consistency across multiple measurements of the same object. This paper studies the evaluation of the precision of measurement systems that measure on a bounded ordinal scale. A bounded ordinal scale consists of a finite number of categories that have a specific order. Based on an inventory of methods for the evaluation of precision for other types of measurement scales, the article proposes two approaches. The first approach is based on a latent variable model and is a variant of the intraclass correlation method. The second approach is a non-parametric approach, the results of which are, however, rather difficult to interpret. The approaches are illustrated with an artificial data set and an industrial data set. Copyright © 2004 John Wiley & Sons, Ltd. [source] Modelling and optimization of district heating and industrial energy system,an approach to a locally deregulated heat marketINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 5 2004Alemayehu Gebremedhin Abstract Regions with densely concentration of industries and district heating systems (DHS) could be interesting study object from the light of an integrated heat market on local basis. System analysis with a widened system boundary could be used as an approach to evaluate the benefit of an integrated heat supply system. In this study, an energy system model consisting of totally seven different participants is designed and the optimization results of the system analysis are presented. With applied data and assumptions, the study shows that a significant amount of the heat demand within two sub-systems can be covered by heat supply from the heat market (the entire heat comes from two industries). Shadow prices, which can be used for heat pricing, indicate the advantage of an integrated system. The system cost reduction through integration and the availability of several actors with diverse energy supply system, makes the region under study an interesting area to prove a locally deregulated heat market. Copyright © 2004 John Wiley & Sons, Ltd. [source] Extent of Nontimber Resource Extraction in Tropical Forests: Accessibility to Game Vertebrates by Hunters in the Amazon BasinCONSERVATION BIOLOGY, Issue 2 2003Carlos A. Peres We conducted a basin-wide geographic information system analysis of the nonmotorized accessibility of Amazonian NTFP extraction and estimated the proportion of the Amazon drainage basin within Brazil ( 3.74 million km 2 ) that can be accessed on foot from the nearest navigable river or functional road. We use a long-term series of standardized line-transect vertebrate censuses conducted throughout the region to illustrate the effects of physical accessibility on wildlife densities in terms of hunting pressure as a function of distance from the nearest point of access. Population abundance in large-bodied, prime-target species preferred by game hunters tended to increase at greater distances from the access matrix, whereas small-bodied species ignored by hunters usually showed the reverse trend. In addition, we estimated the proportion of presumably inviolate core areas within nature, extractive, and indigenous reserves of Brazilian Amazonia that are prohibitively remote and unlikely to be overhunted; for instance, only 1.16% of the basin-wide area is strictly protected on paper and is reasonably safe from extractive activities targeted to game vertebrates and other valuable NTFPs. Finally, we discuss the concept of truly undisturbed wildlands in the last major tropical forest regions by distinguishing potentially overharvested areas from those that remain largely or entirely pristine and that maintain viable populations of a full complement of harvest-sensitive species. Resumen: Las actividades de extracción enfocadas en un amplio rango de productos forestales no maderables ( NTFPs ) son omnipresentes en los bosques tropicales. Sin embargo, la extensión de bosques estructuralmente intactos en una determinada región afectada por esta forma de perturbación críptica ha sido escasamente documentada. Realizamos un análisis GIS del acceso no motorizado para la extracción NTFP en el Amazonas y estimamos la proporción de la desembocadura de la cuenca amazónica ( ,3.74 millones de km2 ) a la cual se puede acceder a pie a partir del río navegable o la carretera funcional más cercana. Utilizamos series de censos de vertebrados a largo plazo empleando transectos en línea estandarizados a lo largo de la región para ejemplificar los efectos del acceso físico sobre las densidades de vida silvestre en términos de presión de caza como función de la distancia al punto de acceso más cercano. La abundancia poblacional de especies de cuerpo grande que son blancos preferidos por los cazadores tendió a crecer a mayores distancias de la matriz de acceso, mientras que las especies de cuerpo pequeño ignoradas por los cazadores generalmente muestran la tendencia inversa. Además, estimamos la proporción de áreas medulares presuntamente inviolables dentro de las reservas naturales, extractivas e indígenas del Amazonas brasileño que son prohibitivamente remotas y poco probables de ser sobreexplotadas: por ejemplo, solo el 1.16% del área de la cuenca estrictamente proyectada en papel está razonablemente a salvo de las actividades extractivas de los vertebrados de caza y otras NTFPs valiosas. Finalmente, discutimos el concepto de tierras silvestres verdaderamente no perturbadas en las grandes regiones de bosque tropical restantes diferenciando las áreas potencialmente sobreexplotadas de aquellas que son en su mayor parte o totalmente prístinas y que mantienen poblaciones viables de un complemento total de especies sensibles a la cosecha. [source] DEFINING STANDARD OF CARE IN THE DEVELOPING WORLD: THE INTERSECTION OF INTERNATIONAL RESEARCH ETHICS AND HEALTH SYSTEMS ANALYSISDEVELOPING WORLD BIOETHICS, Issue 2 2005ADNAN A. HYDER ABSTRACT In recent years there has been intense debate regarding the level of medical care provided to ,standard care' control groups in clinical trials in developing countries, particularly when the research sponsors come from wealthier countries. The debate revolves around the issue of how to define a standard of medical care in a country in which many people are not receiving the best methods of medical care available in other settings. In this paper, we argue that additional dimensions of the standard of care have been hitherto neglected, namely, the structure and efficiency of the national health system. The health system affects locally available medical care in two important ways: first, the system may be structured to provide different levels of care at different sites with referral mechanisms to direct patients to the appropriate level of care. Second, inefficiencies in this system may influence what care is available in a particular locale. As a result of these two factors locally available care cannot be equated with a national ,standard'. A reasonable approach is to define the national standard of care as the level of care that ought to be delivered under conditions of appropriate and efficient referral in a national system. This standard is the minimum level of care that ought to be provided to a control group. There may be additional moral arguments for higher levels of care in some circumstances. This health system analysis may be helpful to researchers and ethics committees in designing and reviewing research involving standard care control groups in developing country research. [source] Non-parametric,parametric model for random uncertainties in non-linear structural dynamics: application to earthquake engineeringEARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS, Issue 3 2004Christophe Desceliers Abstract This paper deals with the transient response of a non-linear dynamical system with random uncertainties. The non-parametric probabilistic model of random uncertainties recently published and extended to non-linear dynamical system analysis is used in order to model random uncertainties related to the linear part of the finite element model. The non-linearities are due to restoring forces whose parameters are uncertain and are modeled by the parametric approach. Jayne's maximum entropy principle with the constraints defined by the available information allows the probabilistic model of such random variables to be constructed. Therefore, a non-parametric,parametric formulation is developed in order to model all the sources of uncertainties in such a non-linear dynamical system. Finally, a numerical application for earthquake engineering analysis is proposed concerning a reactor cooling system under seismic loads. Copyright © 2003 John Wiley & Sons, Ltd. [source] Molecular and functional characterization of a novel splice variant of ANKHD1 that lacks the KH domain and its role in cell survival and apoptosiscFEBS JOURNAL, Issue 16 2005Melissa C. Miles Multiple ankyrin repeat motif-containing proteins play an important role in protein,protein interactions. ANKHD1 proteins are known to possess multiple ankyrin repeat domains and a single KH domain with no known function. Using yeast two-hybrid system analysis, we identified a novel splice variant of ANKHD1. This splice variant of ANKHD1, which we designated as HIV-1 Vpr-binding ankyrin repeat protein (VBARP), does not contain the signature KH domain, and codes for only a single ankyrin repeat motif. We characterized VBARP by molecular and functional analysis, revealing that VBARP is ubiquitously expressed in different tissues as well as cell lines of different lineage. In addition, blast searches indicated that orthologs and homologs to VBARP exist in different phyla, suggesting that VBARP might be evolutionarily conserved, and thus may be involved in basic cellular function(s). Furthermore, biochemical analysis revealed the presence of two VBARP isoforms coding for 69 and 49 kDa polypeptides, respectively, that are primarily localized in the cytoplasm. Functional analysis using short interfering RNA approaches indicate that this gene product is essential for cell survival through its regulation of caspases. Taken together, these results indicate that VBARP is a novel splice variant of ANKHD1 and may play a role in cellular apoptosis (antiapoptotic) and cell survival pathway(s). [source] Eliciting information about organizational culture via ladderingINFORMATION SYSTEMS JOURNAL, Issue 3 2002Gordon Rugg Abstract. Eliciting information about organizational culture is an important part of system analysis and design. However, eliciting knowledge of this sort is difficult. Laddering is an established technique that is particularly suitable for eliciting information about goals and for eliciting explanations, which are important issues when investigating organizational culture. This paper describes the method, its strengths and limitations, its use in several case studies and its relation to other elicitation techniques. Recommendations for further work are given. [source] Design and implementation of an interleaved soft-switching converter with output voltage doublerINTERNATIONAL JOURNAL OF CIRCUIT THEORY AND APPLICATIONS, Issue 2 2010B.-R. Lin Abstract An interleaved pulse-width modulation (PWM) converter with less power switches is presented in this paper. The buck type of active clamp circuit is used to recycle the energy stored in the leakage inductor of a transformer. The zero voltage switching (ZVS) turn-on of power switches is realized by the resonance during the transition interval of power switches. At the secondary side of transformers, two full-wave rectifiers with dual-output configuration are connected in parallel to reduce the current stresses of the secondary windings of transformers. In the proposed converter, power switches can accomplish two functions of the interleaved PWM modulation and active clamp feature at the same time. Therefore, the circuit components in the proposed converter are less than that of the conventional interleaved ZVS forward converter. The operation principle and system analysis of the proposed converter are provided in detail. Experimental results for a 280,W prototype operated at 100,kHz are provided to demonstrate the effectiveness of the proposed converter. Copyright © 2008 John Wiley & Sons, Ltd. [source] A comprehensive techno-economic analysis method for power generation systems with CO2 captureINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 4 2010Gang Xu Abstract A new comprehensive techno-economic analysis method for power generation systems with CO2 capture is proposed in this paper. The correlative relationship between the efficiency penalty, investment increment, and CO2 avoidance cost is established. Through theoretical derivation, typical system analysis, and variation trends investigation, the mutual influence between technical and economic factors and their impacts on the CO2 avoidance cost are studied. At the same time, the important role that system integration plays in CO2 avoidance is investigated based on the analysis of a novel partial gasification CO2 recovery system. The results reveal that for the power generation systems with CO2 capture, the efficiency penalty not only affects the costs on fuel, but the incremental investment cost for CO2 capture (U.S.$,kW,1) as well. Consequently, it will have a decisive impact on the CO2 avoidance cost. Therefore, the added attention should be paid to improve the technical performance in order to reduce the efficiency penalty in energy system with CO2 capture and storage. Additionally, the system integration may not only decrease the efficiency penalty, but also simplify the system structure and keep the investment increment at a low level, and thereby it reduces the CO2 avoidance cost significantly. For example, for the novel partial gasification CO2 recovery system, owing to system integration, its efficiency can reach 42.2%, with 70% of CO2 capture, and its investment cost is only 87$,kW,1 higher than that of the reference IGCC system, thereby the CO2 avoidance cost is only 6.23$,t,1 CO2. The obtained results provide a comprehensive technical,economical analysis method for energy systems with CO2 capture useful for reducing the avoidance costs. Copyright © 2009 John Wiley & Sons, Ltd. [source] Energy and exergy system analysis of thermal improvements of blast-furnace plantsINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 2 2006Andrzej Zi Abstract The blast-furnace process dominating in the production of steel all over the world is still continuously improved due to its effectiveness (exergy efficiency is about 70%). The thermal improvement consist in an increase of the temperature of the blast and its oxygen enrichment, as well as the injection of cheaper auxiliary fuels. The main aim is to save coke because its consumption is the predominating item of the input energy both in the blast-furnace plant and in ironworks. Besides coke also other energy carriers undergo changes, like the consumption of blast, production of the chemical energy of blast-furnace gas, its consumption in Cowper-stoves and by other consumers, as well as the production of electricity in the recovery turbine. These changes affect the whole energy management of ironworks due to the close connections between energy and technological processes. That means the production of steam, electricity, compressed air, tonnage oxygen, industrial water, feed water undergo changes as well. In order to determine the system changes inside the ironworks a mathematical model of the energy management of the industrial plant was applied. The results of calculations of the supply of energy carriers to ironworks can then be used to determine the cumulative energy and exergy consumption basing on average values of cumulative energy and exergy indices concerning the whole country. Such a model was also used in the system analysis of exergy losses. Copyright © 2005 John Wiley & Sons, Ltd. [source] Modelling and optimization of district heating and industrial energy system,an approach to a locally deregulated heat marketINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 5 2004Alemayehu Gebremedhin Abstract Regions with densely concentration of industries and district heating systems (DHS) could be interesting study object from the light of an integrated heat market on local basis. System analysis with a widened system boundary could be used as an approach to evaluate the benefit of an integrated heat supply system. In this study, an energy system model consisting of totally seven different participants is designed and the optimization results of the system analysis are presented. With applied data and assumptions, the study shows that a significant amount of the heat demand within two sub-systems can be covered by heat supply from the heat market (the entire heat comes from two industries). Shadow prices, which can be used for heat pricing, indicate the advantage of an integrated system. The system cost reduction through integration and the availability of several actors with diverse energy supply system, makes the region under study an interesting area to prove a locally deregulated heat market. Copyright © 2004 John Wiley & Sons, Ltd. [source] New IQC for quasi-concave nonlinearitiesINTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 7 2001Alexandre Megretski Abstract A new set of integral quadratic constraints (IQC) is derived for a class of ,rate limiters', modelled as a series connections of saturation-like memoryless nonlinearities followed by integrators. The result, when used within the standard IQC framework (in particular, with finite gain/passivity-based argiments, Lyapunov theory, structured singular values, etc.), is expected to be widely useful in nonlinear system analysis. For example, it enables ,discrimination' between ,saturation-like' and ,deadzone-like' nonlinearities and can be used to prove stability of systems with saturation in cases when replacing the saturation block by another memoryless nonlinearity with equivalent slope restrictions makes the whole system unstable. In particular, it is shown that the L2 gain of a unity feedback system with a rate limiter in the forward loop cannot exceed \sqrt{2}. In addition, a new, more flexible version of the general IQC analysis framework is presented, which relaxes the homotopy and boundedness conditions, and is more aligned with the language of the emerging IQC software. Copyright © 2001 John Wiley & Sons, Ltd. [source] Miscibility and rheological properties of poly(vinyl chloride)/styrene,acrylonitrile blends prepared by melt extrusionJOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2007Hyun Sik Moon Abstract Styrene,acrylonitrile (SAN) with acrylonitrile (AN) concentrations of 11.6,26 wt % and ,-methylstyrene acrylonitrile (,MSAN) with a wide range of AN concentrations are miscible with poly(vinyl chloride) (PVC) through solution blending. Here we examine the rheological properties and miscibility of PVC/SAN and PVC/,MSAN blends prepared by melt extrusion for commercial applications. We have investigated the rheological properties of the blends with a rheometer and a melt indexer. The PVC/SAN and PVC/,MSAN blends have a low melting torque, a long degradation time, and a high melt index, and this means that they have better processability than pure PVC. The miscibility of the blends has been characterized with differential scanning calorimetry, dynamic mechanical thermal analysis, and advanced rheometrics expansion system analysis. The miscibility of the blends has also been characterized with scanning electron microscopy. The SAN series with AN concentrations of 24,31 wt % is immiscible with PVC by melt extrusion, whereas ,MSAN with 31 wt % AN is miscible with PVC, even when they are blended by melt extrusion, because of the strong interaction between PVC and ,MSAN. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007 [source] Mating system and genetic diversity of a rare desert legume Ammopiptanthus nanus (Leguminosae)JOURNAL OF SYSTEMATICS EVOLUTION, Issue 1 2009Guo-Qing CHEN Abstract Ammopiptanthus nanus is an endangered evergreen shrub endemic to the deserts of central Asia and plays an important role in delaying further desertification. We examined allozyme variation and AFLP diversity in A. nanus populations and investigated the mating system of this species using progeny arrays assayed for polymorphic allozyme loci. Mating system analysis in the Keyi'eryongke'er population showed low levels of out-crossing, and strong inbreeding depression. Low levels of genetic variation were detected at both population (allozyme, Pp= 14.0%, A= 1.14, He= 0.031; AFLP, Pp= 14.5%, Shannon's information index I= 0.063) and species (allozyme, Pp= 21.1%, A= 1.21, He= 0.040; AFLP, Pp= 20.9%, I= 0.083) levels; while moderate genetic differentiation existed among populations, as indicated by allozymes (GST= 0.081) and AFLP (GST= 0.151,0.193). Founder effect, bottlenecks in evolutionary history, the mixed mating system and co-ancestry may have influenced the level of genetic diversity in A. nanus. Markers of both types provide new insights for conservation management, indicating that the Biao'ertuokuoyi and Keyi'eryongke'er populations should be given priority for in situ conservation and regarded as seed sources for ex situ conservation. [source] Polymorphic microsatellite markers for paternity assessment in southern calamari Sepioteuthis australis (Cephalopoda: Loliginidae)MOLECULAR ECOLOGY RESOURCES, Issue 4 2003L. M. Van Camp Abstract Recent decades have seen the fast growth of cephalopod fisheries but their management is compromised by the critical gaps in our knowledge of cephalopod life histories. Molecular markers are invaluable tools for studying the evolutionary significance and management implications of variation in mating systems. We have developed seven polymorphic microsatellite loci for mating system analysis in the southern calamari Sepioteuthis australis Quoy & Gaimard 1833 using magnetic enrichment and colony hybridization techniques. Observed heterozygosities range from 32% to 100% and will have sufficient power to examine the relative success of alternate mating strategies in S. australis. [source] Critical properties and stability of stationary solutions in multitransonic pseudo-Schwarzschild accretionMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 1 2006Soumini Chaudhury ABSTRACT For inviscid, rotational accretion flows, both isothermal and polytropic, a simple dynamical system analysis of the critical points has given a very accurate mathematical scheme to understand the nature of these points, for any pseudo-potential by which the flow may be driven on to a Schwarzschild black hole. This allows us for a complete classification of the critical points for a wide range of flow parameters, and shows that the only possible critical points for this kind of flow are saddle points and centre-type points. A restrictive upper bound on the angular momentum of critical solutions has been established. A time-dependent perturbative study reveals that the form of the perturbation equation, for both isothermal and polytropic flows, is invariant under the choice of any particular pseudo-potential. Under generically true outer boundary conditions, the inviscid flow has been shown to be stable under an adiabatic and radially propagating perturbation. The perturbation equation has also served the dual purpose of enabling and understanding the acoustic geometry for inviscid and rotational flows. [source] Characterization of agrobacteria from weeping fig (Ficus benjamina)PLANT PATHOLOGY, Issue 5 2001A. Zoina Ficus benjamina plants, galled both at epi- and hypogeous parts, were observed in Italy and in The Netherlands, and these were the first records of the appearance of weeping fig crown gall in Europe. A total of 241 Agrobacterium isolates was obtained from 41 tumours and studied for their morphological, physiological and phytopathological characters. Two main groups of agrobacteria were distinguished by their colony morphology and through classical biovarietal tests that allowed allocation of 86 isolates into biovar 1 and 155 into an intermediate biovar rather different from any of the three biovars defined for agrobacteria. Most of the isolates were unable to utilize mannopine, nopaline or octopine as C and N sources; only 62 strains utilized nopaline. However, when nonopine-utilizing strains were inoculated into F. benjamina, only nopaline was detected in the developing tumours. BIOLOG ML 1Ô system analysis applied to 50 representative strains allowed identification of the biovar 1 isolates as Agrobacterium tumefaciens and most of the intermediate biovar isolates as the newly proposed species Agrobacterium fici. Analysis of sensitivity to a set of 14 antibiotics confirmed the allocation of the 50 strains into two well defined main clusters matching the BIOLOG identification. Out of 141 tumorigenic isolates, 66 were sensitive in vitro to agrocine 84, but four of these strains showed scarce or no sensitivity to the antagonist A. radiobacter K84 when tested in fig plants. The two types of agrobacteria could usually be isolated from the same tumours. Tumorigenic strains were able to induce tumours in six herbaceous plant species, in eight to 10 out of 12 woody plants and in six to eight out of nine Ficus species, indicating a wide host-range Ti plasmid. Agrobacteria were able to survive and move in the vascular system of galled ficus plants and to induce tumour growth in stem-cutting propagated plants. Moreover, agrobacteria were detected in many healthy F. benjamina plants as part of the endophytic microflora. These findings suggest potential for spread of the disease through latently infected plant propagation material produced as cuttings or by tissue culture. [source] Comparison of two new approaches to variable ordering for binary decision diagramsQUALITY AND RELIABILITY ENGINEERING INTERNATIONAL, Issue 3 2001L. M. Bartlett Abstract Fault tree analysis, FTA, is one of the most commonly used techniques for safety system analysis. There can be problems with the efficiency and accuracy of the approach when dealing with large tree structures. Recently the binary decision diagram (BDD) methodology has been introduced which significantly aids the analysis of the fault tree diagram. The approach has been shown to improve both the efficiency of determining the minimal cut sets of the fault tree, and also the accuracy of the calculation procedure used to quantify the top event parameters. To utilize the BDD technique the fault tree structure needs to be converted into the BDD format. Converting the fault tree is relatively straightforward but requires the basic events of the tree to be placed in an ordering. The ordering of the basic events is critical to the resulting size of the BDD, and ultimately affects the performance and benefits of this technique. There are a number of variable ordering heuristics in the literature, however the performance of each depends on the tree structure being analysed. These heuristic approaches do not yield a minimal BDD structure for all trees, some approaches generate orderings that are better for some trees but worse for others. Within this paper two approaches to the variable ordering problem have been discussed. The first is the pattern recognition approach of neural networks, which is used to select the best ordering heuristic for a given fault tree from a set of alternatives. The second examines a completely new heuristic approach of using the structural importance of a component to produce a ranked ordering. The merits of each are discussed and the results compared. Copyright © 2001 John Wiley & Sons, Ltd. [source] Factors affecting methane production and mitigation in ruminantsANIMAL SCIENCE JOURNAL, Issue 1 2010Masaki SHIBATA ABSTRACT Methane (CH4) is the second most important greenhouse gas (GHG) and that emitted from enteric fermentation in livestock is the single largest source of emissions in Japan. Many factors influence ruminant CH4 production, including level of intake, type and quality of feeds and environmental temperature. The objectives of this review are to identify the factors affecting CH4 production in ruminants, to examine technologies for the mitigation of CH4 emissions from ruminants, and to identify areas requiring further research. The following equation for CH4 prediction was formulated using only dry matter intake (DMI) and has been adopted in Japan to estimate emissions from ruminant livestock for the National GHG Inventory Report: Y = ,17.766 + 42.793X , 0.849X2, where Y is CH4 production (L/day) and X is DMI (kg/day). Technologies for the mitigation of CH4 emissions from ruminants include increasing productivity by improving nutritional management, the manipulation of ruminal fermentation by changing feed composition, the addition of CH4 inhibitors, and defaunation. Considering the importance of ruminant livestock, it is essential to establish economically feasible ways of reducing ruminant CH4 production while improving productivity; it is therefore critical to conduct a full system analysis to select the best combination of approaches or new technologies to be applied under long-term field conditions. [source] Design and analysis of an IEEE 802.16e-based OFDMA communication systemBELL LABS TECHNICAL JOURNAL, Issue 4 2007Krishna Balachandran IEEE 802.16e has emerged as a strong candidate standard for future wireless systems primarily because it offers the potential for high spectral efficiency, flexible spectrum options (e.g., 2,6 GHz), scalable carrier bandwidth options (e.g., from 1.25 MHz to 20 MHz), multiple duplexing options (time and frequency division duplex), various subchannelization options, and, unlike its IEEE 802.16 predecessors, mobility. Because of the recent emergence of IEEE 802.16e and the complexity it poses in system analysis, there is little published work in the literature regarding the actual system capacity/ throughput performance of IEEE 802.16e for high data rate services. In this paper, we investigate the link and system level performance on the downlink of an IEEE 802.16e-based orthogonal frequency division multiple access (OFDMA) communication system and provide recommendations on high performance IEEE 802.16e system design and deployment configurations. We also propose dynamic resource allocation methods that may be used in OFDMA systems and investigate their performance. @ 2007 Alcatel-Lucent. [source] Origin of Paleofluids in Dabashan Foreland Thrust Belt: Geochemical Evidence of 13C, 18O and 87Sr/86Sr in Veins and Host RocksACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 5 2010ZENG Jianhui Abstract: In the last ten years, with important discoveries from oil and gas exploration in the Dabashan foreland depression belt in the borderland between Shanxi and Sichuan provinces, the relationship between the formation and evolution of, and hydrocarbon accumulation in, this foreland thrust belt from the viewpoint of basin and oil and gas exploration has been studied. At the same time, there has been little research on the origin of fluids within the belt. Based on geochemical system analysis including Z values denoting salinity and research on ,13C, ,18O and 87Sr/86Sr isotopes in the host rocks and veins, the origin of paleofluids in the foreland thrust belt is considered. There are four principal kinds of paleofluid, including deep mantle-derived, sedimentary, mixed and meteoric. For the deep mantle-derived fluid, the ,13C is generally less than ,5.0,PDB, ,18O less than ,10.0,PDB, Z value less than 110 and 87Sr/86Sr less than 0.70600; the sedimentary fluid is mainly marine carbonate-derived, with the ,13C generally more than ,2.0,PDB, ,18O less than ,10.0,PDB, Z value more than 120 and 87Sr/86Sr ranging from 0.70800 to 0.71000; the mixed fluid consists mainly of marine carbonate fluid (including possibly a little mantle-derived fluid or meteoric water), with the ,13C generally ranging from ,2.0, to ,8.0,PDB, ,18O from ,10.0, to ,18.0, PDB, Z value from 105 to 120 and 87Sr/86Sr from 0.70800 to 0.71000; the atmospheric fluid consists mainly of meteoric water, with the ,13C generally ranging from 0.0, to ,10.0,PDB, ,18O less than ,8.0%cPDB, Z value less than 110 and 87Sr/86Sr more than 0.71000. The Chengkou fault belt encompasses the most complex origins, including all four types of paleofluid; the Zhenba and Pingba fault belts and stable areas contain a simple paleofluid mainly of sedimentary type; the Jimingsi fault belt contains mainly sedimentary and mixed fluids, both consisting of sedimentary fluid and meteoric water. Jurassic rocks of the foreland depression belt contain mainly meteoric fluid. [source] A Systematic Analysis of Coal Accumulation ProcessACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 3 2008CHENG Aiguo Abstract: Formation of coal seam and coal-rich zone is an integrated result of a series of factors in coal accumulation process. The coal accumulation system is an architectural aggregation of coal accumulation factors. It can be classified into 4 levels: the global coal accumulation super-system, the coal accumulation domain mega-system, the coal accumulation basin system, and the coal seam or coal seam set sub-system. The coal accumulation process is an open, dynamic, and grey system, and is meanwhile a system with such natures as aggregation, relevance, entirety, purpose-orientated, hierarchy, and environment adaptability. In this paper, we take coal accumulation process as a system to study origin of coal seam and coal-rich zone; and we will discuss a methodology of the systematic analysis of coal accumulation process. As an example, the Ordos coal basin was investigated to elucidate the application of the method of the coal accumulation system analysis. [source] | |||||||||||||||||||