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Business operations must effectively utilize real-time information presented by the manufacturing execution system for the identification and analysis of key improvements, finite resources can be put to better use, and implement e...
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Business operations must effectively utilize real-time information presented by the manufacturing execution system for the identification and analysis of key improvements, finite resources can be put to better use, and implement effective quality improvements. This study analyzed overall loss through time loss, performance loss, and material loss by expanding the manufacture value process. Overall process loss (OPL) and overall line loss (OLL) were developed as indexes to select key improvement targets. First, Pareto analysis was used to identify process. The ICAM (Integrated Computer Aided Manufacturing) Definition (IDEF) was then employed to inform improvement decisions regarding the loss item. Finally, new key improvement goals were identified from the updated OLL, with continual improvement. The contributions of this study are the development of the indexes, OPL and OLL, based on overall loss, the improvement decision model, and the construction of a mechanism whereby sustainable reduction of overall loss can be achieved.
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Due to the increasing requirements for efficiency, the wide range of characteristics and the improved possibilities of modern development and production processes, compressors in turbochargers have become more individualized in or...
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Due to the increasing requirements for efficiency, the wide range of characteristics and the improved possibilities of modern development and production processes, compressors in turbochargers have become more individualized in order to adapt to the requirements of internal combustion engines. An understanding of the working mechanisms as well as an understanding of the way that losses occur in the flow allows a reduced development effort during the optimization process. This article presents three-dimensional (3D) Computational Fluid Dynamics (CFD) investigations of the loss mechanisms and quantitative calculations of individual losses. The 3D-CFD method used in this article will reduce the drawbacks of one-dimensional calculation as far as possible. For example, the twist of the blades is taken into account and the "discrete" method is used for loss calculation instead of the "average" method. The results show that at the same blade speed, the clearance loss reaches its maximum with a mass flow of 0.07 kg/s. Secondary losses are highest at low mass flows and reduce as the mass flow increases. However, at high mass flows the secondary loss has a slight increase because of the high velocity gradient. The velocity of the main fluid is high if the mass flow is large, which results in a high friction loss in the internal fluid as well as between the fluid and the casing. A 3D-consideration of impeller design makes the incidence loss change slightly with increased mass flow. The exit angle and instability of the main flow are decisive for the losses in the diffuser.
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The expected annual monetary loss (EAL) is a powerful seismic performance indicator for a building as it quantifies repair and replacement costs considering a wide range of possible earthquake scenarios. Existing methods for the e...
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The expected annual monetary loss (EAL) is a powerful seismic performance indicator for a building as it quantifies repair and replacement costs considering a wide range of possible earthquake scenarios. Existing methods for the estimation of EAL are admirably rigorous but also represent a significant departure from current code assessment methods. By introducing simple loss vs. intensity relationships that are anchored to engineering limit states (set considering both structural and non-structural elements) it is shown that one can predict EAL values quickly, through a closed form expression that could be implemented easily in practice. The validity of the approach is demonstrated by comparing predictions of EAL with those obtained using refined EAL assessments, for a number of case study buildings. The limitations with the accuracy of the approach are discussed and the possibility of developing empirical loss vs. intensity relationships as part of future research is proposed.
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Piezoelectric materials such as polymers (PVDF),copolymers (P(VDF-TrFE)), lead metaniobates orceramic/polymer composites possess high losses. In this case, thecharacterisation method described in IEES Standard onPiezoelectricity 9...
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Piezoelectric materials such as polymers (PVDF),copolymers (P(VDF-TrFE)), lead metaniobates orceramic/polymer composites possess high losses. In this case, thecharacterisation method described in IEES Standard onPiezoelectricity 91987) for low-loss materials is not applicable.Several methods have been proposed to determine the losses byintroducing complex parameters in the piezoelectric constitutiveequations. A number of these methods consider mechanical,dielectric and piezoelectric losses, but others only take intoaccount mechanical and dielectric losses. In this paper, weinvestigate the influence of these types of losses on the electricalimpedance of a thickness mode resonator. This study shows thatpiezoelectric losses have very little effect and that only dielectricand mechanical losses need to be taken into account for transducerdesign. Measurements were also performed on three differentmaterials. The results using our method are compared to those ofpreviously published studies.
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In this conceptual paper, a framework for defining loss calculation methodologies is proposed. Nine basic elements required to define and/or classify loss calculation methodologies are presented. Three elements specifically deal w...
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In this conceptual paper, a framework for defining loss calculation methodologies is proposed. Nine basic elements required to define and/or classify loss calculation methodologies are presented. Three elements specifically deal with substantive policy decisions, one element is about risk management, and the remaining five elements represent process or calculations. Description of each of these elements and how they relate to various loss calculation methodologies are included.
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Classical core loss models such as two components model or modified Steinmetz model are still popular and used by engineers to loss prediction in electrical machines. They may carry to increase discrepancy between calculated and m...
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Classical core loss models such as two components model or modified Steinmetz model are still popular and used by engineers to loss prediction in electrical machines. They may carry to increase discrepancy between calculated and measured values. This discrepancy increases with grain-orientation and with increasing discrepancy from sinusoidal magnetisation conditions. Statistical loss model shows better applicability for loss calculation however, it requires many measurements in frequency domain what is troublesome. The paper presents the frequency behaviour of classical and statistical loss models in grain and non-oriented electrical steel sheets.
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In order to achieve high efficiency and low loss of motor, it is important to accurately grasp the losses caused in motor for each factor. We manufactured a motor loss separation measuring unit. Using this unit, we then made a met...
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In order to achieve high efficiency and low loss of motor, it is important to accurately grasp the losses caused in motor for each factor. We manufactured a motor loss separation measuring unit. Using this unit, we then made a method to measure and separate the losses of the specimen which imitates a motor core. In the evaluation of the mechanical loss, the windage loss during highspeed rotation of the specimen can be separated by measuring the mechanical loss under reduced pressure. In the evaluation of iron loss, it is possible to compare and evaluate the deterioration of iron loss due to shrink-fitting compressive stress using the shrink-fitting simulation mechanism of the stator core, and the deterioration of iron loss due to machining strain in the process of manufacturing the stator core. This time, we conducted an experiment to extract windage loss from mechanical loss and obtained respectable separate measurement results. We confirmed the factors that increase windage loss through the experiment.
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Estimating technical losses is fundamental to the planning and economics of electric power networks. This paper surveys the evolution of the ideas behind energy loss estimation and focuses on the development of the concepts of the...
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Estimating technical losses is fundamental to the planning and economics of electric power networks. This paper surveys the evolution of the ideas behind energy loss estimation and focuses on the development of the concepts of the loss factor and equivalent hours. The paper next identifies difficulties in using maximum demands and the loss factor to estimate energy losses. Based on this analysis, this study proposes an alternative loss estimation approach that relies on the “loss coefficient” as the fundamental parameter for describing load variations in loss estimation. A large load-curve data bank from Brazilian utilities is used to characterize load-curve parameters and provide perspective on the old and new concepts. Practical applications put the proposed ideas into perspective, showing how the use of average demands and loss coefficient can help to make better cable choices, increase accuracy in loss estimation for distribution transformers, and enhance the quality of information in loss estimation analysis.
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Technical losses arise by known physical electricity effects and it is not possible to eliminate them effectively. The paper deals with the 1st version of software tool for technical losses of transmission system lines calculation...
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Technical losses arise by known physical electricity effects and it is not possible to eliminate them effectively. The paper deals with the 1st version of software tool for technical losses of transmission system lines calculation. The inputs are line parameters and measured data databases from control system of the Czech transmission system operator (6EPS company). Outputs are Joule's losses, corona losses and leakage losses for each transmission line. The paper also includes description of input databases structure, calculation result files and computing algorithms.
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The contribution of food availability to food insecurity and poverty reduction, makes food loss an important issue. The study provides findings on the economic and nutritional implications of produce loss at different stages of th...
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The contribution of food availability to food insecurity and poverty reduction, makes food loss an important issue. The study provides findings on the economic and nutritional implications of produce loss at different stages of the common bean value chain and discuss farmers role in reducing losses through their measurement of loss and awareness of loss factors. Average losses at the postharvest handling stage, storage and marketing stage were estimated to be 85.6%, 11.6% and 2.8% of the total loss along the chain respectively. The analysis was extended to determining the economic and nutrient losses along the value chain. Losses contributes to economic losses of $269,417.6 and $8,035.2 at the production and marketing stages respectively. The true cost based on value added loss estimations was however found to be $423,737.8 at the production stage. Findings revealed that out of the total nutrients lost at the post harvest handling stage contributes (88.07%) contributes to majority of the losses compared to the storage stage (11.93%). Losses were found to be caused by unfavourable weather, seed quality, insects, diseases and inefficient handling practices. More than 60% of both producers and traders measured their losses and had a fair understanding of the factors causing losses with a significant difference being observed between measurers and non-measurers. Lack of awareness was not found to be a contributing factor to losses but inability to manage them. Improvement in the capacity of agents to better manage losses is expected to result in lower levels of losses. (C) 2020 Elsevier Ltd. All rights reserved.
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