25 resultados para Total Flow Management

em Chinese Academy of Sciences Institutional Repositories Grid Portal


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``软件危机'',这一始于上世纪~60~年代的概念,始终伴随着软件业的整个历史发展进程。 为了解决该问题,人们逐渐开始借鉴一些传统领域内的管理理论、方法和工具,以期解决软件开发中所面临的问题。其中,更多的是作为一种管理哲学,而不是具体管理方法的全面质量管理(Total Quality Management,TQM),在软件工程领域得到了广泛应用。全面质量管理对于软件工程的影响,一个很重要的方面是促进了软件过程和软件过程改 进的研究、实践。 作为软件过程研究的重要内容,软件过程建模是通过特定的方法对软件过程进行抽象、表示和分析以增加对软件过程的理解,并通过直接或者间接的方式指导实际软件开发活动。为了对软件过程管理活动提供方法和工具支持,人们提出了多种以过程为中心的软件过程工程环境(Process-centered Software Engineering Environment, PSEE),其最终目的是使得实际软件开发活动受软件过程模型的支配。但由于过程模型本身的正确性得不到保证、PSEE中执行的软件过程模型和实际开发过程之间的信息反馈缺乏客观性以及过程模型和实际开发过程之间的抽象层次不同和描述粒度不一致,导致PSEE中执行的软件过程模型和实际开发过程之间经常产生严重的偏差,以至于PSEE对实际开发活动逐渐地失去了支持和指导作用,进而使得投入大量成本所开发的软件过程模型无法发挥其应有的作用。 针对这些问题,本文提出了一种具有严格操作语义的图形化软件过程建模方法。由于在具有图形化表示方式的同时,又具备严格的操作语义,因此基于该方法所描述的软件过程比较易于分析。特别是,通过模型检测技术验证软件过程模型本身的正确性,可以减少由模型错误所导致的不一致;通过比较预定义的过程模型和实际开发过程,可以发现两者间的不一致并及时地消除。同时,具有严格操作语义的软件过程建模方法,可以为软件过程执行提供良好的支持。 首先,本文提出了一种具有严格操作语义的图形化建模语言——TRISO/ML。该语言具有图形化的表示方式,可以更容易地为软件工程人员所接受,以及更好地满足过程表示对易用性和可理解性的需求。该语言同时具有严格的操作语义,可以映射到多元PI演算,从而能够更准确地描述软件过程,避免歧义的产生。更为重要的是,该语言从行为角度出发,能够以一致的方式描述软件过程中的各种实体及其相互间的并发、同步和通信。 其次,在TRISO/ML语言的基础之上,提出了一系列的软件过程分析方法。主要研究如何利用多元PI演算的理论、方法和工具以及软件验证技术,对软件过程进行分析和验证。软件过程分析的研究主要集中在如下两个方面:a)软件过 程模型本身正确性的验证,以确保该模型准确地描述了所希望表达的内容。b)比较两个过程模型是否等价。 然后,基于软件过程移动性概念,研究了如何通过软件过程结构的变化支持过程的动态执行。软件过程移动性概念反映了软件过程执行时,由于软件过程实体的动态交互,导致构成软件过程的实体及其相互间的关系不断地发生变化。 软件过程移动性这一概念的提出,使得软件过程实体之间的关系可以在软件过程执行时动态地确立和调整,软件过程的定义随着过程信息的不断丰富而逐步地细化和明确,从而能够以更灵活的方式支持软件过程的表示和执行。 最后,描述了支持TRISO/ML的原型工具,包括基于TRISO/ML的过程表示、多元PI演算语义描述的自动生成,以及进一步的分析和验证。

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供应链管理使企业在变化的市场环境中有效地与其它企业合作 ,取得集体竞争优势。本文首先讨论了后勤学与供应链管理的定义和之间的关系。本文认为供应链管理的核心是物流与信息流的控制。物流控制决策主要包括操作层次的库存补充和运输路径规划 ,以及战略层次的设施地点规划。信息流管理跨越部门与企业的界限将相关的应用集成起来。动态联盟协调各企业内部的生产经营活动 ,战略性地决定物流与信息流的构形。

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We described here a new method for the determination of total calcium in plasma. The method is based on the precipitation of calcium with excess oxalate and the measurement of residual oxalate by flow injection analysis with Ru(bpy)(3)(2+) electrochemiluminescent detection. It has the advantages of extremely stable reagent, user-friendly instrument, high selectivity, good analytical recovery, wide dynamic range, and nice correlation with atomic absorption spectroscopy. The calibration plot for calcium is linear over a concentration range from 0.5 mmol L-1 to 4.8 mmol L-1, which is wider than those obtained by most other methods. The analytical recoveries for plasma calcium are 98.4-101.2% with coefficients of variation (CVs) of 1.96-2.52%. The within-day CVs range from 0.76% to 0.95%, and between-day CVs were from 1.12% to 1.46%. The time for each injection is one minute. Because the proposed method can be readily carried out on increasingly popular instruments for Ru(bpy)(3)(2+) ECL immunoassays and DNA probe assays, Ru(bpy)32+ ECL method is suitable for routine clinical analysis of calcium.

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Measurement of iron and manganese is very important in evaluating the quality of natural waters. We have constructed an automated Fe(II), total dissolved iron(TDI), Mn(II), and total dissolved manganese(TDM) analysis system for the quality control of underground drinking water by reverse flow injection analysis and chemiluminescence detection(rFIA-CL), The method is based on the measurement of the metal-catalyzed light emission from luminol oxidation by potassium periodate. The typical signal is a narrow peak, in which the height is proportional to light emitted and hence to the concentration of metal ions. The detection limits were 3 x 10(-6) mu g ml(-1) for Fe(II) and the linear range extents up to 1.0 x 10(-4) and 5 x 10(-6) mu g ml(-1) for Mn(II) cover a linear range to 1.0 x 10(-4) mu g ml(-1). This method was used for automated in-situ monitoring of total dissolved iron and total dissolved in underground water during water treatment. (C) 1997 Elsevier Science B.V.

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Alpine meadow and shrub are the main pasture types on the Tibetan Plateau, and they cover about 35% of the total land area. In order to understand the structural and functional aspects of the alpine ecosystem and to promote a sustainable animal production system, the Haibei Alpine Meadow Research Station was established in 1976. A series of intensive studies on ecosystem structure and function, including the energy flow and nutrient cycling of the ecosystem, were the main tasks during the first 10 years. Meanwhile, studies with 5 different grazing intensities on both summer and winter pasture have been conducted. In the early years of the 1990s, the research station started to focus its research work on global warming, biodiversity and sustainable animal production systems in pastoral areas. Various methods for improving degraded pasturelands have been developed in the region.

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A fifth-order theory for solving the problem of interaction between Stokes waves and exponential profile currents is proposed. The calculated flow fields are compared with measurements. Then the errors caused by the linear superposition method and approximate theory are discussed. It is found that the total wave-current field consists of pure wave, pure current and interaction components. The shear current not only directly changes the flow field, but also indirectly does sx, by changing the wave parameters due to wave-current interaction. The present theory can predict the wave kinematics on shear currents satisfactorily. The linear superposition method may give rise to more than 40% loading error in extreme conditions. When the apparent wave period is used and the Wheeler stretching method is adopted to extrapolate the current, application of the approximate theory is the best.

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The controlled equations defined in a physical plane are changed into those in a computational plane with coordinate transformations suitable for different Mach number M(infinity). The computational area is limited in the body surface and in the vicinities of detached shock wave and sonic line. Thus the area can be greatly cut down when the shock wave moves away from the body surface as M(infinity) --> 1. Highly accurate, total variation diminishing (TVD) finite-difference schemes are used to calculate the low supersonic flowfield around a sphere. The stand-off distance, location of sonic line, etc. are well comparable with experimental data. The long pending problem concerning a flow passing a sphere at 1.3 greater-than-or-equal-to M(infinity) > 1 has been settled, and some new results on M(infinity) = 1.05 have been presented.

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The effects of the free-stream thermo-chemical state on the test model flow field in the high-enthalpy tunnel are studied numerically. The properties of the free-stream, which is in thermo-chemical non-equilibrium, are determined by calculating the nozzle flow field. A free-stream with total enthalpy equal to the real one in the tunnel while in thermo-chemical equilibrium is constructed artificially to simulate the natural atmosphere condition. The flow fields over the test models (blunt cone and Apollo command capsule model) under both the non-equilibrium and the virtual equilibrium free-stream conditions are calculated. By comparing the properties including pressure, temperature, species concentration and radiation distributions of these two types of flow fields, the effects of the non-equilibrium state of the free-stream in the high-enthalpy shock tunnel are analyzed.

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The induced flow fields by internal solitary waves and its actions on cylindrical piles in density stratified ocean with a basic density profile and a basic velocity profile are investigated. Some results, such as the time evolution of flow fields and hydrodynamic forces on the piles are yielded both by theoretical analysis and numerical calculation for general and specific cases. Several kinds of ambient sea conditions of the South China Sea are specified for numerical simulation. Moreover, the effects of relative density difference, depth ratio and wave steepness on maximal total force and total torque are analyzed.

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Abstract—Burst-and-coast is the most common locomotion type in freely routine swimming of koi carps (Cyprinus carpio koi), which consists of a burst phase and a coast phase in each cycle and mostly leads to a straight-line trajectory. Combining with the tracking experiment, the flow physics of koi carp’s burst-andcoast swimming is investigated using a novel integrated CFD method solving the body-fluid interaction problem. The dynamical equations of a deforming body are formulated. Following that, the loose-coupled equations of the body dynamics and the fluid dynamics are numerically solved with the integrated method. The two burst modes, MT (Multiple Tail-beat) and HT (Half Tail-beat), which have been reported by the experiments, are investigated by numerical simulations in this paper. The body kinematics is predicted and the flow physics is visualized, which are in good agreement with the corresponding experiments. Furthermore, the optimization on the energy cost and several critical control mechanisms in burst-and-coast swimming of koi carps are explored, by varying the parameters in its selfpropelled swimming. In this paper, energetics is measured by the two mechanical quantities, total output power CP and Froude efficiency Fr. Results and discussion show that from the standpoint of mechanical energy, burst-and-coast swimming does not actually save energy comparing with steady swimming at the same average speed, in that frequently changing of speed leads to decrease of efficiency.

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The study presented here was carried out to obtain the actual solids flow rate by the combination of electrical resistance tomography and electromagnetic flow meter. A new in-situ measurement method based on measurements of the Electromagnetic Flow Meters (EFM) and Electrical Resistance Tomography (ERT) to study the flow rates of individual phases in a vertical flow was proposed. The study was based on laboratory experiments that were carried out with a 50 mm vertical flow rig for a number of sand concentrations and different mixture velocities. A range of sand slurries with median particle size from 212 mu m to 355 mu m was tested. The solid concentration by volume covered was 5% and 15%, and the corresponding density of 5% was 1078 kg/m(3) and of 15% was 1238 kg/m(3). The flow velocity was between 1.5 m/s and 3.0 m/s. A total of 6 experimental tests were conducted. The equivalent liquid model was adopted to validate in-situ volumetric solids fraction and calculate the slip velocity. The results show that the ERT technique can be used in conjunction with an electromagnetic flow meter as a way of measurement of slurry flow rate in a vertical pipe flow. However it should be emphasized that the EFM results must be treated with reservation when the flow pattern at the EFM mounting position is a non-homogenous flow. The flow rate obtained by the EFM should be corrected considering the slip velocity and the flow pattern.

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Leptobrachium ailaonicum is a vulnerable anuran restricted to a patchy distribution associated with small mountain streams surrounded by forested slopes at mid-elevations (approximately 2000-2600 m) in the subtropical Mount Wuliang and Mount Ailao ranges in southwest China (Yunnan Province) and northern Vietnam. Given high habitat specificity and lack of suitable habitat in lower elevations between these ranges, we hypothesized limited gene flow between populations throughout its range. We used two mitochondrial genes to construct a phylogeographic pattern within this species in order to test our hypothesis. We also examined whether this phylogeographic pattern is a response to past geological events and/or climatic oscillations. A total of 1989 base pairs were obtained from 81 individuals of nine populations yielding 51 unique haplotypes. Both Bayesian and maximum parsimony phylogenetic analyses revealed four deeply divergent and reciprocally monophyletic mtDNA lineages that approximately correspond to four geographical regions separated by deep river valleys. These results suggest a long history of allopatric separation by vicariance. The distinct geographic distributions of four major clades and the estimated divergence time suggest spatial and temporal separations that coincide with climatic and paleogeographic changes following the orogeny and uplift of Mount Ailao during the late Miocene to mid Pliocene in southwest China. At the southern distribution, the presence of two sympatric yet differentiated clades in two areas are interpreted as a result of secondary contact between previously allopatric populations during cooler Pleistocene glacial cycles. Analysis of molecular variance indicates that most of the observed genetic variation occurs among the four regions implying long-term interruption of maternal gene flow, suggesting that L ailaonicum may represent more than one distinct species and should at least be separated into four management units corresponding to these four geographic lineages for conservation. (C) 2009 Elsevier Inc. All rights reserved.

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Microorganisms play an important role in removing pollutants from constructed wetlands. We investigated the microbial characteristics in a novel integrated vertical-flow constructed wetland (IVCW), which has been in operation in Wuhan, China since 1998. We used phospholipid fatty acid (PLFA) and amoA gene to analyze the structure and diversity of the microbial community within the IVCW. PLFA results suggested that the amount of bacterial PLFA was significantly higher than that of fungal PLFA, but the total microbial biomass represented by PLFA index was low in the system. Microbial spatial distribution showed significantly higher bacterial (both G(+) and G(-)) and fungal biomass in the surface than in the subsurface layers. The ratios of monounsaturated to branched PLFA demonstrated that an anaerobic layer sandwiched by two aerobic layers existed in the IVCW, consistent with the redox potential results. Analysis of the amoA revealed the presence of Nitrosomonas-like sequences in the surface substrate of the downflow chamber and apparent diversities of ammonia-oxidizing bacteria in the system. These results suggest that microorganisms, despite their relatively low biomass, have inhabited the IVCW, and the results will offer some valuable information on microbe to system designers and managers.

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A comparative study was conducted to reveal the differentiate effects of eight different filter media including gravel, zeolites, anthracite, shale, vermiculite, ceramic filter media, blast furnace steel slag and round ceramsite. The study mainly related to the eight different filter media's removal performances of organic matter, nitrogen and phosphorus in the vertical flow constructed wetland simulated system, which treating wastewater at hydraulic loading rate of 1000-2500 mm/d. The results indicated that the removal effects were closely related to the physical and chemical properties of medium materials. Anthracite-filled system had the highest removal rate for the total organic carbon (TOC), up to 70%, and the removal rates of other systems ranged from 20% to 30%. As for the five-day biochemical oxygen demand (BOD5), anthracite-filled and steel slag-filled systems had the highest removal rates, also up to 70%, as well as other systems all exceeded 50%. At the same time, for the total nitrogen (TN) and NH4(+)-N, the zeolites-filled and ceramic-filled systems had the best performances with the removal rates of more than 70%, the other way round, the removal rates of other systems were only about 20%. The distinguishable effects were also observed in removal performances of total phosphorus (TP) and total dissoluble phosphorus (TDP). The removal rates of TP and TDP in steel slag-filled systems were more than 90%, a much higher value, followed by that of the anthracite-filled system, more than 60%, but those of other systems being the less. Our study provided a potential mechanism to optimize the filter media design for the vertical flow constructed wetlands.

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Phosphorus removal performance and a possible mechanism for the phosphorus removal from an eutrophic lake water were investigated using a medium-scale integrated vertical constructed wetland (combined vertical and reverse-vertical systems) from April, 11, 2001 to September, 28, 2004. Environmental factors affecting phosphorus removal and release profiles were monitored simultaneously under hydraulic loads from 400 to 2000 mm per day. The phosphorus removal rate varied with the environmental conditions. The removal rate for acidic influent water was superior to that for alkaline influent water. The substrate in the wetland chamber acted as a buffer to regulate the pH value of the water sample. As regards the water temperature, no significant differences were observed for the removal rate of total phosphorus (TP) and soluble reactive phosphorus (SRP) between low (lower than 15 degrees C) medium (16-25 degrees C) and high temperature (higher than 26 degrees C) conditions. Under a hydraulic load of 400 mm per day, the removal rate reached over 70%, the highest value achieved in this work. In addition, the highest hydraulic load of 2000 mm/d did not result in the lowest removal rate, as had been expected. After a two-year high hydraulic load test, the removal rate decreased significantly. Phosphorous release from the substrate was examined using a spatial sampling method. Depth profiles of total phosphorus and different states of phosphorus present in the substrate were recorded. This further study demonstrated that binding of phosphorus by iron and calcium might be another major factor in the removal and release of TP and SRP in this wetland system. The distribution of the speciated phosphorus showed that the amount of phosphorus captured in the substrate of the down-flow chamber was significantly higher than that captured in the up-flow chamber, suggesting that the up-flow chamber was the main source of phosphorus release in this constructed wetland.