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利用通用流量计算机实现体积流量/质量流量的转换
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作者 姜新芳 杨位存 刘全荣 《自动化仪表》 CAS 北大核心 2000年第12期25-26,共2页
介绍利用智能流量计算机,在保证精度的情况下,实现了体积流量转换成质量流量。具体介绍了转换方法、现场接线与校验结果。
关键词 量转换 体积 质量 算机 液氨 流理计 尿素
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美国ORE超声波流量计故障分析
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作者 刘金峰 谷峪 刘文瑞 《山东水利》 1999年第C00期27-28,共2页
美国ORE公司制造的超声波流量计,适用于管道和明渠。它利用超声波技术来测量多条相互平行声道上的平均流速,并计算过水流量。 当对流量计进行修理时,应根据状态灯的指示情况和显示的状态码数值,进行故障原因分析。1 状态灯 打开电源开关... 美国ORE公司制造的超声波流量计,适用于管道和明渠。它利用超声波技术来测量多条相互平行声道上的平均流速,并计算过水流量。 当对流量计进行修理时,应根据状态灯的指示情况和显示的状态码数值,进行故障原因分析。1 状态灯 打开电源开关,检查位于声路连结器面板左侧的绿色电源指示灯。这些灯指示了系统各种电源的工作情况。正常情况下,3个灯都应亮。若3个灯都不亮,则检查是否有电。若有电,检查系统的保险丝,若保险丝是好的,就可能是系统电源坏了。 展开更多
关键词 超声波流理计 故障分析 平均 过水
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Identification of Sewage Monitoring Data Based on Mathematical Statistics
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作者 万玉山 邹涛 +3 位作者 李大伟 温馨 沈梦 陈艳秋 《Agricultural Science & Technology》 CAS 2017年第4期656-659,共4页
In order to reduce the enormous pressure to environmental monitoring work brought by the false sewage monitoring data, Grubbs method, box plot, t test and other methods are used to make depth analysis to the data, pro... In order to reduce the enormous pressure to environmental monitoring work brought by the false sewage monitoring data, Grubbs method, box plot, t test and other methods are used to make depth analysis to the data, providing a set of technological process to identify the sewage monitoring data, which is convenient and simple. 展开更多
关键词 Mathematical statistics Monitoring data Technological process
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Design and parametric optimization of thermal management of lithium-ion battery module with reciprocating air-flow 被引量:3
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作者 刘燕平 欧阳陈志 +1 位作者 江清柏 梁波 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第10期3970-3976,共7页
Single cell temperature difference of lithium-ion battery(LIB) module will significantly affect the safety and cycle life of the battery. The reciprocating air-flow module created by a periodic reversal of the air flo... Single cell temperature difference of lithium-ion battery(LIB) module will significantly affect the safety and cycle life of the battery. The reciprocating air-flow module created by a periodic reversal of the air flow was investigated in an effort to mitigate the inherent temperature gradient problem of the conventional battery system with a unidirectional coolant flow with computational fluid dynamics(CFD). Orthogonal experiment and optimization design method based on computational fluid dynamics virtual experiments were developed. A set of optimized design factors for the cooling of reciprocating air flow of LIB thermal management was determined. The simulation experiments show that the reciprocating flow can achieve good heat dissipation, reduce the temperature difference, improve the temperature homogeneity and effectively lower the maximal temperature of the modular battery. The reciprocating flow improves the safety, long-term performance and life span of LIB. 展开更多
关键词 lithium-ion battery thermal management reciprocating air-flow temperature difference orthogonal optimization SIMULATION
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Approach for workflow modeling using π-calculus 被引量:5
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作者 杨东 张申生 《Journal of Zhejiang University Science》 EI CSCD 2003年第6期643-650,共8页
As a variant of process algebra, π calculus can describe the interactions between evolving processes. By modeling activity as a process interacting with other processes through ports, this paper presents a new appro... As a variant of process algebra, π calculus can describe the interactions between evolving processes. By modeling activity as a process interacting with other processes through ports, this paper presents a new approach: representing workflow models using π calculus. As a result, the model can characterize the dynamic behaviors of the workflow process in terms of the LTS (Labeled Transition Semantics) semantics of π calculus. The main advantage of the workflow model's formal semantic is that it allows for verification of the model's properties, such as deadlock free and normal termination. Moreover, the equivalence of workflow models can be checked through weak bisimulation theorem in the π calculus, thus facilitating the optimization of business processes. 展开更多
关键词 Workflow modeling π calculus Business process modeling
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ANALYSIS OF FORWARD-FLYBACK CONVERTER EMPLOYING TWO SWITCHES AND TWO TRANSFORMERS 被引量:1
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作者 HONGFeng SHIdian-jiang YANYang-guang 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2004年第4期311-316,共6页
A novel forward-flyback converter employing two switches and two transformers is presented. Two diodes of the primary side enable the voltage stress of two switches to be clamped at the input voltage ,which is lower t... A novel forward-flyback converter employing two switches and two transformers is presented. Two diodes of the primary side enable the voltage stress of two switches to be clamped at the input voltage ,which is lower than that of a conventional forward-flyback converter. Two transformers offer the following advantages. Firstly, the turns of primary transformer winding are reduced to half of that of a conventional forward-flyback converter with a single transformer; Secondly, the use of two transformers enables the smaller low-profile cores to be utilized, thus facilitating a low-profile design. The unequal condition of turn ratios is compared with the equal condition of turn ratios. When two turn ratios are unequal, the power distribution between the two transformers can be easily designed. Finally, experimental results verify the above analyses. 展开更多
关键词 power supply CONVERTER design
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Dust dispersion and management in underground mining faces 被引量:45
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作者 Kurnia Jundika Candra Sasmito Agus Pulung Mujumdar Arun Sadashiv 《International Journal of Mining Science and Technology》 SCIE EI 2014年第1期39-44,共6页
Presence of fine dust in air causes serious health hazard for mine operators resulting in such serious problems as coal workers’pneumoconiosis and silicosis.Major sources of dust appear of course along the mining fac... Presence of fine dust in air causes serious health hazard for mine operators resulting in such serious problems as coal workers’pneumoconiosis and silicosis.Major sources of dust appear of course along the mining face where the minerals are extracted.Proper control and management are required to ensure safe working environment in the mine.Here,we utilize the computational fluid dynamic(CFD)approach to evaluate various methods used for mitigating dust dispersion from the mining face and for ensuring safe level of dust concentration in the mine tunnel for safety of the operators.The methods used include:application of blowing and exhaust fans,application of brattice and combination of both.The results suggest that among the examined methods,implementation of appropriately located brattice to direct the flow from the main shaft to the mining face is the most effective method to direct dust particles away from the mining face. 展开更多
关键词 Dust dispersion Modeling Undergrouand mine Ventilation
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A ROBUST OPTICAL FLOW COMPUTATION 被引量:2
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作者 Lu Zongqing XieWeixin Pei Jihong 《Journal of Electronics(China)》 2007年第5期635-641,共7页
This paper presents a new method for robust and accurate optical flow estimation.The sig- nificance of this work is twofold.Firstly,the idea of bi-directional scheme is adopted to reduce the model error of optical flo... This paper presents a new method for robust and accurate optical flow estimation.The sig- nificance of this work is twofold.Firstly,the idea of bi-directional scheme is adopted to reduce the model error of optical flow equation,which allows the second order Taylor's expansion of optical flow equation for accurate solution without much extra computational burden;Secondly,this paper establishs a new optical flow equation based on LSCM (Local Structure Constancy Model) instead of BCM (Brightness Constancy Model),namely the optical flow equation does not act on scalar but on tensor-valued (ma- trix-valued) field,due to the two reason:(1) structure tensor-value contains local spatial structure information,which provides us more useable cues for computation than scalar;(2) local image structure is less sensitive to illumination variation than intensity,which weakens the disturbance of non-uniform illumination in real sequences.Qualitative and quantitative results for synthetic and real-world scenes show that the new method can produce an accurate and robust results. 展开更多
关键词 Optical flow TENSOR Brightness Constancy Model (BCM) Local Structure Constancy Model (LSCM)
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Lightweight SOA-Based Twin-Engine Architecture for Enterprise Systems in Fixed and Mobile Environments 被引量:1
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作者 Tongguang Zhang Shuai Zhao +3 位作者 Budan Wu Maurizio Farina Bo Cheng Junliang Chen 《China Communications》 SCIE CSCD 2016年第9期183-194,共12页
Mobile devices as a popular computing platform for enterprise systems have enabled certain tasks to be executed out of office.However,the work may be interrupted due to the server shutdown or network disconnection whe... Mobile devices as a popular computing platform for enterprise systems have enabled certain tasks to be executed out of office.However,the work may be interrupted due to the server shutdown or network disconnection when employees access traditional single-engine Business Process Management System.To overcome this defect,we present a lightweight twin-engine architecture based on Service Oriented Architecture(SOA).In this paper,we discuss in detail the design and implementation of the architecture,and present a trigger mechanism to activate engines according to the states of hybrid environments since it is critical for the two types of engines to cooperate closely in hybrid environments with fixed and mobile computing resources.The experimental results validate the usability of the architecture. 展开更多
关键词 TWIN-ENGINE SOA enterprise system mobile environment
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Physical modelling and scale effects of air-water flows on stepped spillways 被引量:5
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作者 CHANSON Hubert GONZALEZ Carlos A. 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2005年第3期243-250,共8页
During the last three decades, the introduction of new construction materials (e.g. RCC (Roller Compacted Concrete), strengthened gabions) has increased the interest for stepped channels and spillways. However stepped... During the last three decades, the introduction of new construction materials (e.g. RCC (Roller Compacted Concrete), strengthened gabions) has increased the interest for stepped channels and spillways. However stepped chute hydraulics is not simple, because of different flow regimes and importantly because of very-strong interactions between entrained air and turbu- lence. In this study, new air-water flow measurements were conducted in two large-size stepped chute facilities with two step heights in each facility to study experimental distortion caused by scale effects and the soundness of result extrapolation to pro- totypes. Experimental data included distributions of air concentration, air-water flow velocity, bubble frequency, bubble chord length and air-water flow turbulence intensity. For a Froude similitude, the results implied that scale effects were observed in both facilities, although the geometric scaling ratio was only Lr=2 in each case. The selection of the criterion for scale effects is a critical issue. For example, major differences (i.e. scale effects) were observed in terms of bubble chord sizes and turbulence levels al- though little scale effects were seen in terms of void fraction and velocity distributions. Overall the findings emphasize that physical modelling of stepped chutes based upon a Froude similitude is more sensitive to scale effects than classical smooth-invert chute studies, and this is consistent with basic dimensional analysis developed herein. 展开更多
关键词 Physical modelling Scale effects Stepped spillways Air entrainment Air-water flow measurements
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Biologic Waste: Consistent Performance with an Alternating Field
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作者 Hans-Jürgen Huber 《Journal of Environmental Science and Engineering(B)》 2017年第12期589-592,共4页
Biomass plants often struggle to capture flow measurements reliably. High amounts of dry solids and fats complicate the measurement with an MID (Magnetic-Inductive) flowmeter and make it susceptible to faults. To ov... Biomass plants often struggle to capture flow measurements reliably. High amounts of dry solids and fats complicate the measurement with an MID (Magnetic-Inductive) flowmeter and make it susceptible to faults. To overcome this impediment, the waste water treatment plant in Innsbruck, Austria, relies on electromagnetic pulsed AC (Alternating Current) flowmeters. Compared to pulsed DC (Direct Current) devices, AC devices are able to build up magnetic fields that are ten times stronger. Equipped with this capability, the Sitrans Transmag 2 is able to guarantee a constant and also high measuring accuracy, zero point stability and signal strength regardless of impurities in the medium or fluctuations in the magnetic field. 展开更多
关键词 Biomass wastewater treatment process instrumentation flow measurement pulsed AC meter pulsed DC meter Transmag 2.
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Urban Green Space Planning Based on Computational Fluid Dynamics Model and Landscape Ecology Principle:A Case Study of Liaoyang City,Northeast China 被引量:9
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作者 ZHOU Yuan SHI Tiemao +4 位作者 HU Yuanman GAO Chang LIU Miao FU Shilei WANG Shizhe 《Chinese Geographical Science》 SCIE CSCD 2011年第4期465-475,共11页
As a result of environmental degradation,urban green space has become a key issue for urban sustainable development.This paper takes Liaoyang City in Northeast China as an example to develop green space planning using... As a result of environmental degradation,urban green space has become a key issue for urban sustainable development.This paper takes Liaoyang City in Northeast China as an example to develop green space planning using the computational fluid dynamics (CFD) model,landscape ecological principles and Geographical Information System (GIS).Based on the influencing factors of topography,building density and orientation,Shou Mountain,Longding Mountain and the Taizi River were selected as the urban ventilation paths to promote wind and oxygen circulation.Oxygen concentration around the green spaces gradually decreased with wind speed increase and wind direction change.There were obvious negative correlation relationships between the oxygen dispersion concentration and urban layout factors such as the building plot ratio and building density.Comparison with the field measurements found that there was significant correlation relationship between simulated oxygen concentration and field measurements (R 2=0.6415,p<0.001),moreover,simulation precision was higher than 92%,which indicated CFD model was effective for urban oxygen concentration simulation.Only less than 10% areas in Liaoyang City proper needed more green space urgently to improve oxygen concentration,mainly concentrated in Baitai and west Wensheng districts.Based on land-scape ecology principle,green space planning at different spatial scales were proposed to create a green space network system for Liaoyang City,including features such as green wedges,green belts and parks.Totally,about 2012 ha of green space need to be constructed as oxygen sources and ventilation paths.Compared with the current green space pattern,proposed green space planning could improve oxygen concentration obviously.The CFD model and research results in this paper could provide an effective way and theory support for sustainable development of urban green space. 展开更多
关键词 green space computational fluid dynamics oxygen dispersion pattern landscape ecology Liaoyang City proper
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Influence of A Hyperons ^1S0 Superfluidity on the Direct Urca Processes with Hyperons 被引量:1
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作者 许妍 刘广洲 +2 位作者 吴姚睿 王红岩 张峰 《Communications in Theoretical Physics》 SCIE CAS CSCD 2011年第9期521-524,共4页
In the framework of the relativistic mean field theory (RMFT), the relativistic energy losses of the direct Urea processes with hyperons (Y-DURCA ) for reactions A → p + e + υe and ≡^-→ A+e+υe are studied... In the framework of the relativistic mean field theory (RMFT), the relativistic energy losses of the direct Urea processes with hyperons (Y-DURCA ) for reactions A → p + e + υe and ≡^-→ A+e+υe are studied in neutron stars. We calculate the energy gap of A hyperons and investigate the effects of the ^1S0 superfluidity (SF) of A hyperons on the Y-DURCA processes. The calculated results are in line with the recent experimental data △ BAA ~ 1.01 ±0.20-0.11^+0.18 MeV. The results indicate that the ^1S0 SF of A hyperons exists in most density ranges of happening the two reactions. The theoretical cooling curves are in agreement with observation data. 展开更多
关键词 hyperons superfluidity direct Urca processes with hyperons neutron star
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An Enhanced Hadoop Heartbeat Mechanism for MapReduce Task Scheduler Using Dynamic Calibration 被引量:3
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作者 Xinzhu Lu Keatkeong Phang 《China Communications》 SCIE CSCD 2018年第11期93-110,共18页
MapReduce is a popular program- ming model for processing large-scale datasets in a distributed environment and is a funda- mental component of current cloud comput- ing and big data applications. In this paper, a hea... MapReduce is a popular program- ming model for processing large-scale datasets in a distributed environment and is a funda- mental component of current cloud comput- ing and big data applications. In this paper, a heartbeat mechanism for MapReduce Task Scheduler using Dynamic Calibration (HMTS- DC) is proposed to address the unbalanced node computation capacity problem in a het- erogeneous MapReduce environment. HMTS- DC uses two mechanisms to dynamically adapt and balance tasks assigned to each com- pute node: 1) using heartbeat to dynamically estimate the capacity of the compute nodes, and 2) using data locality of replicated data blocks to reduce data transfer between nodes. With the first mechanism, based on the heart- beats received during the early state of the job, the task scheduler can dynamically estimate the computational capacity of each node. Us- ing the second mechanism, unprocessed Tasks local to each compute node are reassigned and reserved to allow nodes with greater capacities to reserve more local tasks than their weaker counterparts. Experimental results show that HMTS-DC performs better than Hadoop and Dynamic Data Placement Strategy (DDP) in a dynamic environment. Furthermore, an en- hanced HMTS-DC (EHMTS-DC) is proposed bv incorporatin historical data. In contrastto the "slow start" property of HMTS-DC, EHMTS-DC relies on the historical computation capacity of the slave machines. The experimental results show that EHMTS-DC outperforms HMTS-DC in a dynamic environment. 展开更多
关键词 dynamic load-balancing HADOOP MAPREDUCE replication mechanism heartbeatnechanism
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A prototype of workflow management system for construction design projects
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作者 杨明宇 《Journal of Chongqing University》 CAS 2005年第3期144-148,共5页
A great deal of benefits can be achieved if information and process are integrated within the building design project. This paper aims to establish a prototype of workflow management system for construction design pro... A great deal of benefits can be achieved if information and process are integrated within the building design project. This paper aims to establish a prototype of workflow management system for construction design project through the application of workflow technology. The composition and function of prototype is presented to satisfy the needs of information share and process integration. By integrating all subsystems and modules of the prototype, the whole system can deal with design information-flow modeling, emulating and optimizing, task planning and distributing, automatic tracking and monitoring, as well as network service, etc. In this way, the collaborative design environment of building design proiect is brought into being. 展开更多
关键词 workflow management system collaborative desian Intearation modelina simulatina and optimizina
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Continuous query scheduler based on operators clustering
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作者 M.Sami Soliman 谭冠政 《Journal of Central South University》 SCIE EI CAS 2011年第3期782-790,共9页
Data stream management system (DSMS) provides convenient solutions to the problem of processing continuous queries on data streams.Previous approaches for scheduling these queries and their operators assume that each ... Data stream management system (DSMS) provides convenient solutions to the problem of processing continuous queries on data streams.Previous approaches for scheduling these queries and their operators assume that each operator runs in separate thread or all operators combine in one query plan and run in a single thread.Both approaches suffer from severe drawbacks concerning the thread overhead and the stalls due to expensive operators.To overcome these drawbacks,a novel approach called clustered operators scheduling (COS) is proposed that adaptively clusters operators of the query plan into a number of groups based on their selectivity and computing cost using S-mean clustering.Experimental evaluation is provided to demonstrate the potential benefits of COS scheduling over the other scheduling strategies.COS can provide adaptive,flexible,reliable,scalable and robust design for continuous query processor. 展开更多
关键词 data stream management systems operators scheduling continuous query CLUSTERING
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Accounting treatment and internal controls in financial shared services ofmultinational corporations 被引量:2
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作者 CHEN Min 《Journal of Modern Accounting and Auditing》 2010年第8期55-59,共5页
Financial shared services (FSS) play an important role in multinational corporations for the effective cost management. FSS also can reduce errors and fraud so as to achieve perfect internal controls by standardized... Financial shared services (FSS) play an important role in multinational corporations for the effective cost management. FSS also can reduce errors and fraud so as to achieve perfect internal controls by standardized and procedural business processes which are important parts of internal controls. This paper emphasizes on two popular procedures and methods in multinational corporations. One is balance sheet reconciliation. It can illustrate the situation of accounts on an accrual basis which are the focus of internal audit and external audit. The other is Interco-Sop (Intercompany-standard operating procedure) which are important for to ensure the accuracy and effectiveness of accounting system and internal controls. 展开更多
关键词 financial shared services balance sheet reconciliation Interco-Sop
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Swirl Jets in Crossflow at Low Velocity Ratios
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作者 Alexandros Terzis Charilaos Kazakos +2 位作者 Anestis I. Kalfas PavIos K. Zachos Peter Ott 《Journal of Mechanics Engineering and Automation》 2012年第4期256-266,共11页
This investigation examines experimentally the behavior of swirled jets produced by axial flow fans blowing into a crossflow at low velocity ratios. The main difference with non-swirl cases is an asymmetry of the domi... This investigation examines experimentally the behavior of swirled jets produced by axial flow fans blowing into a crossflow at low velocity ratios. The main difference with non-swirl cases is an asymmetry of the dominant kidney vortex and a slight distortion of the jet trace downstream of the injection hole. The effect of jet rotation at relatively low swirl numbers and similar velocity ratios is also investigated by a validated computational analysis tool. The numerical results are analyzed by means of various post-processing procedures, aiming to clarify, quantify and analyze the impact of swirl on the characteristics and the flow domain of a jet in crossflow. In general, swirl introduces an asymmetry in all examined quantities and prevents the penetration of the jet into the crossflow, causing the jet to remain closer to the wall surface. The rotation of the injected fluid results in an imparity of the two parts of the Counter Rotating Vortex Pair (CVP) which is no longer symmetric to the axial centerline plane. High swirl numbers result in the destruction of the CVP and the dominant kidney shape vortex is transformed into a comma shape vortex, rotating close to the wall. 展开更多
关键词 Jet in crossflow SWIRL CFD (computational fluid dynamics).
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Value Creation of Business Process Management (BPM) and Managerial Accounting System (MAS): A Case Study
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作者 Sang Xiangyang Yu Zengbiao 《Journal of Modern Accounting and Auditing》 2014年第7期786-792,共7页
This paper explores the value creation of business process management (BPM) and managerial accounting system (MAS) using a case study. The findings show that BPM shortens the management chain and increases the con... This paper explores the value creation of business process management (BPM) and managerial accounting system (MAS) using a case study. The findings show that BPM shortens the management chain and increases the connections among functions in the organization by right reassignment. Accounting indicators in MAS provide necessary information about business processes, which assists performance evaluation in BPM, and meanwhile, incentive schemes give enough motives, which guide employees to take actions in accordance with the organizational strategies and processes' goals. The information effect and motive effect of MAS increase employees' work satisfaction and their cooperation with each other. In the end, the integration of BPM and MAS improves the organizational economic performance, thus creating value for the organization. The results explain the reason why so much BPM fails in practice, because right assignment, performance evaluation system, and incentive schemes constitute organizational architecture, which is critical to organizational value. Additionally, the value creation of BPM and MAS depends on their coordination with the external environment, the internal situation, and the organizational strategy. From the view of managerial accounting perspective, MAS not only changes with the organization development but also facilitates the organization development. 展开更多
关键词 business process management (BPM) managerial accounting system (MAS) value creation
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Experimental and numerical analysis of secondary disasters induced by oxygen rich combustion within a tunnel 被引量:2
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作者 Cheng Caixia Sun Fuchun +2 位作者 Zhou Xinquan Niu Huiyong Liang De 《Mining Science and Technology》 EI CAS 2011年第6期897-901,共5页
Various physical parameters, including gas concentrations (O2, CO, CH4, and H2) and temperatures at dif- ferent air velocities, were determined for full scale wood fires in the Chongqing Coal Research Institute fire t... Various physical parameters, including gas concentrations (O2, CO, CH4, and H2) and temperatures at dif- ferent air velocities, were determined for full scale wood fires in the Chongqing Coal Research Institute fire test tunnel. Both experimental measurements and numerical simulations are discussed. The numer- ical analysis was performed with the computational fluid dynamics software package ''FLUENT''. The results show that the experimental data agree with the simulation results. The results verify that Roberts' theory of burning is correct. They also prove that the air velocity is the key factor that determines the type of combustion. Also, it is shown that secondary disasters are unlikely for oxygen rich combustion with a limited fire load. 展开更多
关键词 Numerical analysis Combustion type Oxygen-enriched combustion Secondary disasters
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