摘要 :
Lean manufacturing is far from a new concept, and many within the Electronics Assembly (EA) industry are already familiar with the principles and concepts behind it. However, in spite of widespread understanding, the percentage th...
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Lean manufacturing is far from a new concept, and many within the Electronics Assembly (EA) industry are already familiar with the principles and concepts behind it. However, in spite of widespread understanding, the percentage that actually "Live Lean" within EA tends to be far less.
If "Lean" offers such a compelling business advantage, one must critically ask why it has not yet been adopted widely and successfully to date in the "Leading Edge" EA industry? Fortunately today, several technologies and tools available to the EA industry offer new possibilities to realize a major impact as never before.
The intention of this conference paper is to examine some of the new developments in Lean Production Management in EA. Included is a brief look into Lean Production Management concepts such as the coordinating the "Value Stream" supplying products according to customer demand. Lean Production Management can be viewed as "real-time execution-based scheduling" and can keep the factory activity in perfect synchronization with minimum effort.
For high-mix EA operations this paper will also introduce "capacity-driven" beside the "inventory-driven" methods whereby supplying processes are triggered to produce the next item needed when capacity becomes available in downstream processes.
An important consideration of Lean Production Management is effective control of material levels and WIP (Work In Process). Using various methods for tracking and control provides the ability to highlight "Hidden" problems, and with visibility - further enables one in continuous improvement of the production system.
This paper considers tools and technologies available to assist in institutionalizing Lean Production Management. A discussion of a case study is included.
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Based on the observed phenomenon of formation water intrusion in SuTuDen oilfield,i.e.,high reservoir pressure,high constituent percentage of formation water in produced water,stable isotopes tracing,as well as strong-water drive ...
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Based on the observed phenomenon of formation water intrusion in SuTuDen oilfield,i.e.,high reservoir pressure,high constituent percentage of formation water in produced water,stable isotopes tracing,as well as strong-water drive mechanism confirmed by matching & calibrating the production parameters,the authors assessed the impacts of water drive to the production and proposed methods to enhance recovery.The results of water analysis with low TDS(12g/l)indicate the formation water accounts for a significant ratio of the produced water.Among factors affecting production efficiency,the critical ones are fault-fracture characteristics,origins of water,range of hydrodynamic relationship,design plans and well completion.In order to mitigate the negative impacts and increase the positive impacts of these factors,a series of intervention solutions must be considered including combined ESP-Gaslift installation,gas assisted gravity drainage,water or gas injection in selective zones,infill drilling in poorly connected areas.The basement reservoir SuTuDen oilfield is affected by natural water aquifer hence it is necessary to implement recovery solutions such as adjusting the design,maintaining the reservoir pressure,in-fill drilling,artificial lift,stimulating the near-wellbore zone,optimizing the production-injecting regime.When the wells have already been invaded by water,it is very difficult and costly to maintain the cumulative production.Therefore,the mitigation measures should be applied early from the design stage,especially the compatible operating regime,help reducing the water invasion and achieving optimal production.The result of the methods should allow an increase in the overall recovery factor from 36.1% to 39.8%,equivalent to 18.52 MMbbl.
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摘要 :
Based on the observed phenomenon of formation water intrusion in SuTuDen oilfield,i.e.,high reservoir pressure,high constituent percentage of formation water in produced water,stable isotopes tracing,as well as strong-water drive ...
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Based on the observed phenomenon of formation water intrusion in SuTuDen oilfield,i.e.,high reservoir pressure,high constituent percentage of formation water in produced water,stable isotopes tracing,as well as strong-water drive mechanism confirmed by matching & calibrating the production parameters,the authors assessed the impacts of water drive to the production and proposed methods to enhance recovery.The results of water analysis with low TDS(12g/l)indicate the formation water accounts for a significant ratio of the produced water.Among factors affecting production efficiency,the critical ones are fault-fracture characteristics,origins of water,range of hydrodynamic relationship,design plans and well completion.In order to mitigate the negative impacts and increase the positive impacts of these factors,a series of intervention solutions must be considered including combined ESP-Gaslift installation,gas assisted gravity drainage,water or gas injection in selective zones,infill drilling in poorly connected areas.The basement reservoir SuTuDen oilfield is affected by natural water aquifer hence it is necessary to implement recovery solutions such as adjusting the design,maintaining the reservoir pressure,in-fill drilling,artificial lift,stimulating the near-wellbore zone,optimizing the production-injecting regime.When the wells have already been invaded by water,it is very difficult and costly to maintain the cumulative production.Therefore,the mitigation measures should be applied early from the design stage,especially the compatible operating regime,help reducing the water invasion and achieving optimal production.The result of the methods should allow an increase in the overall recovery factor from 36.1% to 39.8%,equivalent to 18.52 MMbbl.
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摘要 :
Dynamic testing soft composite, matrix, and other hyper-viscoelastic materials at high velocities replicating impacts is difficult to perform, either due to the lack of equipment such as a split Hopkinson pressure bar setup, or mo...
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Dynamic testing soft composite, matrix, and other hyper-viscoelastic materials at high velocities replicating impacts is difficult to perform, either due to the lack of equipment such as a split Hopkinson pressure bar setup, or more commonly, the challenges related to sensors and monitoring the dynamic response. For certain soft composites and hydrogel matrices with low moduli on the order of 215,000 Pa, sensing would require a highly sensitive load cell that would also need to survive > 1,000 s~(-1) without failure and/or without digital image correlation allowed as paint or other speckles may not adhere to the specimen surface. Our current research addresses this issue by examining the temperature effects on the material response. By exploring the interaction between temperature and viscoelasticity, we have validated a theoretical framework for performing up to two decades of strain rate testing (100 - 10,000 s~(-1) without altering the impact velocity (7 m/s). and using only a 14 ℃ temperature change. The implications of this research should allow us to examine strain rate effects for certain soft polymer composites at loading rates exceeding the capabilities of our instruments without any new equipment or sensors.
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摘要 :
Dynamic testing soft composite, matrix, and other hyper-viscoelastic materials at high velocities replicating impacts is difficult to perform, either due to the lack of equipment such as a split Hopkinson pressure bar setup, or mo...
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Dynamic testing soft composite, matrix, and other hyper-viscoelastic materials at high velocities replicating impacts is difficult to perform, either due to the lack of equipment such as a split Hopkinson pressure bar setup, or more commonly, the challenges related to sensors and monitoring the dynamic response. For certain soft composites and hydrogel matrices with low moduli on the order of 215,000 Pa, sensing would require a highly sensitive load cell that would also need to survive > 1,000 s~(-1) without failure and/or without digital image correlation allowed as paint or other speckles may not adhere to the specimen surface. Our current research addresses this issue by examining the temperature effects on the material response. By exploring the interaction between temperature and viscoelasticity, we have validated a theoretical framework for performing up to two decades of strain rate testing (100 - 10,000 s~(-1) without altering the impact velocity (7 m/s). and using only a 14 ℃ temperature change. The implications of this research should allow us to examine strain rate effects for certain soft polymer composites at loading rates exceeding the capabilities of our instruments without any new equipment or sensors.
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Linear algebra is an ideal tool to redefine symbolic methods with the goal to achieve better scalability. In solving the abductive Horn propositional problem, the transpose of a program matrix has been exploited to develop an effi...
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Linear algebra is an ideal tool to redefine symbolic methods with the goal to achieve better scalability. In solving the abductive Horn propositional problem, the transpose of a program matrix has been exploited to develop an efficient exhaustive method. While it is competitive with other symbolic methods, there is much room for improvement in practice. In this paper, we propose to optimize the linear algebraic method for abduction using partial evaluation. This improvement considerably reduces the number of iterations in the main loop of the previous algorithm. Therefore, it improves practical performance especially with sparse representation in case there are multiple subgraphs of conjunctive conditions that can be computed in advance. The positive effect of partial evaluation has been confirmed using artificial benchmarks and real Failure Modes and Effects Analysis (FMEA)-based datasets.
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Combustion issued from an eight-hole, direct-injection spray was experimentally studied in a constant-volume pre-burn combustion vessel using simultaneous high-speed diffused back-illumination extinction imaging (DBIEI) and OH* ch...
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Combustion issued from an eight-hole, direct-injection spray was experimentally studied in a constant-volume pre-burn combustion vessel using simultaneous high-speed diffused back-illumination extinction imaging (DBIEI) and OH* chemiluminescence. DBIEI has been employed to observe the liquid-phase of the spray and to quantitatively investigate the soot formation and oxidation taking place during combustion. The fuel-air mixture was ignited with a plasma induced by a single-shot Nd:YAG laser, permitting precise control of the ignition location in space and time. OH* chemiluminescence was used to track the high-temperature ignition and flame. The study showed that increasing the delay between the end of injection and ignition drastically reduces soot formation without necessarily compromising combustion efficiency. For long delays between the end of injection and ignition (1.9 ms) soot formation was eliminated in the main downstream charge of the fuel spray. However, poorly atomized and large droplets formed at the end of injection (dribble) eventually do form soot near the injector even when none is formed in the main charge. The quantitative soot measurements for these spray and ignition scenarios, resolved in time and space, represents a significant new achievement. Reynolds-averaged Navier-Stokes (RANS) simulations were performed to assess spray mixing and combustion. An analysis of the predicted fuel-air mixture in key regions, defined based upon experimental observations, was used to explain different flame propagation speeds and soot production tendencies when varying ignition timing. The mixture analysis indicates that soot production can be avoided if the flame propagates into regions where the equivalence ratio (Φ) is already below 2. Reactive RANS simulations have also been performed, but with a poor match against the experiment, as the flame speed and heat-release rate are largely over estimated. This modeling weakness appears related to a very high level of turbulent viscosity predicted for the high-momentum spray in the RANS simulations, which is an important consideration for modeling ignition and flame propagation in mixtures immediately created by the spray.
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Variability in process-based service compositions needs to be explicitly modeled and managed in order to facilitate service/process customization and increase reuse in service/process development. While related work has been able ...
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Variability in process-based service compositions needs to be explicitly modeled and managed in order to facilitate service/process customization and increase reuse in service/process development. While related work has been able to capture variability and variability dependencies within a composition, these approaches fail to capture variability dependencies between the composition and partner services. Consequently, these approaches cannot address the situation when a composite service is orchestrated from partner services some of which are customizable. In this paper, we propose a feature-based approach that is able to effectively model variability within and across compositions. The approach is supported by a process development methodology that enables the systematic reuse and management of variability. We develop a prototype system supporting extended BPMN 2.0 to demonstrate the feasibility of our approach.
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摘要 :
Variability in process-based service compositions needs to be explicitly modeled and managed in order to facilitate service/process customization and increase reuse in service/process development. While related work has been able ...
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Variability in process-based service compositions needs to be explicitly modeled and managed in order to facilitate service/process customization and increase reuse in service/process development. While related work has been able to capture variability and variability dependencies within a composition, these approaches fail to capture variability dependencies between the composition and partner services. Consequently. these approaches cannot address the situation when a composite service is orchestrated from partner services some of which are customizable. In this paper, we propose a feature-based approach that is able to effectively model variability within and across compositions. The approach is supported by a process development methodology that enables the systematic reuse and management of variability. We develop a prototype system supporting extended BPMN 2.0 to demonstrate the feasibility of our approach.
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Trucking companies can obtain permits from state agencies allowing them to haul oversize and
overweight (OSOW) loads. Most permit systems assign a specific route to be followed that
accounts for various network travel restrictions...
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Trucking companies can obtain permits from state agencies allowing them to haul oversize and
overweight (OSOW) loads. Most permit systems assign a specific route to be followed that
accounts for various network travel restrictions. The routes assigned in these permits can
provide a wealth of information for different types of transportation analyses. Unfortunately, the
permit data is not always generated by a Geographic Information System (GIS) or archived in a
manner that facilitates analysis in a GIS platform. This paper presents a methodology that was
developed to process archived permit records from the West Virginia Department of
Transportation (WVDOT) so that they could be imported into GIS and plotted using the existing
WVDOT Linear Referencing System (LRS). Some agencies do not have a GIS-based OSOW
permitting system, and those who use a GIS permitting systems are still faced with the challenge
of integrating archive data with existing GIS/LRS platforms. The methodology presented in this
paper should be widely applicable for those facing such challenges. The automated procedure
was able to assign an LRS code and map 91.4% of the permits that contained route data for the
month of July 2011.
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