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Viewing 211 to 240 of 21600
2015-04-14
Journal Article
2015-01-1699
Kan Zha, Stephen Busch, Paul C. Miles, Sameera Wijeyakulasuriya, Saurav Mitra, P. K. Senecal
Asymmetrical in-cylinder flow structure has been reported in previous studies in a small-bore Diesel engine. It has been demonstrated that this flow field asymmetry leads to an asymmetrical mixture preparation process. To understand the evolution of this asymmetry, it is necessary to characterize the in-cylinder flow over the full compression stroke. Moreover, since bowl-in-piston cylinder geometries can substantially change the in-cylinder flow, characterization of these flows in light-duty engines requires the use of geometrically correct pistons. In this work, a realistic flow has been realized via a transparent piston top with the conventional re-entrant bowl geometry. However, optical distortion caused by the complex bowl geometry greatly complicates the analysis of images taken through the bottom of the piston; for example in the measurement of swirl-plane velocities using particle image velocimetry (PIV).
2015-04-14
Journal Article
2015-01-0210
S Kevin Chen, Li-Chun Chien, Masaki Nagashima, Joel Van Ess, Sam Hashemi
Abstract Misfire detection and monitoring on US passenger vehicles are required to comply with detailed and specific requirements contained in the OBD-II regulations. Numerous technical papers and patents discuss various methods and metrics for detecting misfire in conventional all-cylinder firing engines. However, the current methods are generally not suitable for detecting misfires in a dynamic skip fire engine. For example, a detection approach based on peak crankshaft angular acceleration may work well in conventional, all-cylinder firing engine operation, since it is expected that crankshaft acceleration will remain generally consistent for a given operating condition. In a skip fire engine, any cylinder or cycle may be skipped. As a result, the crankshaft acceleration peaks and profiles may change abruptly as the firing sequence changes. This paper presents two approaches for detecting misfires in a dynamic skip fire engine.
2015-04-14
Journal Article
2015-01-0869
Ningsheng Qiao, Chandrasekar Krishnamurthy, Nicholas Moore
Air-fuel ratio cylinder imbalance is a condition where the air-fuel ratio in one or more cylinders is different than the other cylinders. When air-fuel ratio cylinder imbalance occurs in one or more cylinders the fuel delivery system is unable to maintain a proper vehicle emission level. It is required for on-board diagnostics to detect air-fuel ratio cylinder imbalance levels which cause the fuel delivery system to be unable to maintain vehicle emissions at or below 1.5 times of any of the applicable FTP (Federal Test Procedure) emission standards. Currently California Air Resources Board (CARB) only requires on-board diagnostics to detect exhaust bank specific air-fuel ratio cylinder imbalance. In the near future CARB will require on-board diagnostics to detect cylinder specific air-fuel ratio cylinder imbalance. This paper presents a non-intrusive approach on determining single cylinder air-fuel ratio imbalance identification (ID) with an oxygen sensor.
2015-04-14
Journal Article
2015-01-0872
Serkan Kulah, Tijs Donkers, Frank Willems
Abstract Cylinder pressure-based combustion control is widely introduced for passenger cars. Benefits include enhanced emission robustness to fuel quality variation, reduced fuel consumption due to more accurate (multi-pulse) fuel injection, and minimized after treatment size. In addition, it enables the introduction of advanced, high-efficient combustion concepts. The application in truck engines is foreseen, but challenges need to be overcome related to durability, increased system costs, and impact on the cylinder head. In this paper, a new single cylinder pressure sensor concept for heavy-duty Diesel engines is presented. Compared to previous studies, this work focuses on heavy-duty Diesel powertrains, which are characterized by a relatively flexible crank shaft in contrast to the existing passenger car applications.
2015-04-14
Journal Article
2015-01-0621
Mina M.S. Kaldas, Kemal Çalışkan, Roman Henze, Ferit Küçükay
Abstract There is an increasing customer demand for adjustable chassis control features which enable adaption of the vehicle comfort and driving characteristics to the customer requirements. One of the most promising vehicle control systems which can be used to change the vehicle characteristics during the drive is the semi-active suspension system. This paper presents a Rule-Optimized Fuzzy Logic controller for semi-active suspension systems which can continuously adjust itself not only according to the road conditions but also to the driver requirements. The proposed controller offers three different control modes (Comfort, Normal and Sport) which can be switched by the driver during driving. The Comfort Mode minimizes the accelerations imposed on the driver and passengers by using a softer damping. On the other hand, the increased damping in Sport Mode provides better road holding capability, which is critical for sporty handling.
2015-04-14
Journal Article
2015-01-1597
Kazuto Yokoyama, Masahiro Iezawa, Hideyuki Tanaka, Keiichi Enoki
Mitsubishi Electric has developed a concept car “EMIRAI 2 xEV” that features an electric vehicle (EV) powertrain for safe, comfortable, and eco-friendly driving experiences in the future. The body of vehicle was exhibited during Tokyo Motor Show 2013 for the first time. xEV is a four-wheel-drive EV that has three motors: a water-cooled front motor and two air-cooled rear motors with integrated inverters. Rear wheels can be driven independently. The degrees of freedom of the actuation can realize improved maneuverability and safety. The vehicle is also equipped with an onboard charger with built-in step down DC/DC converter, an EV control unit, a battery management unit, and an electric power steering. All of the instruments are developed in Mitsubishi Electric Corporation. Motion control systems for xEV have been developed on the basis of our proprietary original motor control technology.
2015-04-14
Journal Article
2015-01-1645
Thomas De Cuyper, Gery Fossaert, Olivier Collet, Stijn Broekaert, Kam Chana, Michel De Paepe, Sebastian Verhelst
Abstract In the development of internal combustion engines, measurements of the heat transfer to the cylinder walls play an important role. These measurements are necessary to provide data for building a model of the heat transfer, which can be used to further develop simulation tools for engine optimization. This research will focus on the Thin Film Gauge (TFG) heat flux sensor. This sensor consists of a platinum RTD (Resistance Temperature Detector) on an insulating Macor® (ceramic) substrate. The sensor has a high frequency response (up to 100 kHz) and is small and robust. These properties make the TFG sensor adequate for measurements in the combustion chamber of an internal combustion engine. To use this sensor, its thermal properties - namely the temperature sensitivity coefficient and the thermal product - must be correctly calibrated.
2015-04-14
Journal Article
2015-01-1646
Ezio Mancaruso, Bianca Maria Vaglieco, Luigi Sequino
Abstract The common realization of the necessity to reduce the use of mineral sources is promoting the use of alternative fuels. Big efforts are being made to replace petroleum derivatives in the internal combustion engines (ICEs). For this purpose it is mandatory to evaluate the behavior of non-conventional fuels in the ICEs. The optical diagnostics have proven to be a powerful tool to analyze the processes that take place inside the engine. In particular, 2d imaging in the infrared range can reveal new details about the effect of the fuel properties since this technique is still not very common. In this work, a comparison between commercial diesel fuel and two non-conventional fuels has been made in an optically accessible diesel engine. The non-conventional fuels are: the first generation biofuel Rapeseed Methyl Ester (RME) and an experimental blend of diesel and a fuel with high glycerol content (HG).
2015-04-14
Journal Article
2015-01-0886
Joseph Pritchard, Wai K. Cheng
The effects of secondary air on the exhaust oxidation of particulate matters (PM) have been assessed in a direct-injection-spark-ignition engine under fuel rich fast idle condition (1200 rpm; 2 bar NIMEP). Substantial oxidation of the unburned feed gas species (CO and HC) and significant reduction of both the particulate number (up to ∼80%) and volume (up to ∼90%) have been observed. The PM oxidation is attributed to the reactions between the PM and the radicals generated in the oxidation of the feed gas unburned species. This hypothesis is supported by the observation that the reduction in PM volume is proportional to the amount of heat release in the secondary oxidation.
2015-04-14
Journal Article
2015-01-0371
Rupesh Sonu Kakade, Prashant Mer
Abstract The human thermal comfort, which has been a subject of extensive research, is a principal objective of the automotive climate control system. Applying the results of research studies to the practical problems require quantitative information of the thermal environment in the passenger compartment of a vehicle. The exposure to solar radiation is known to alter the thermal environment in the passenger compartment. A photovoltaic-cell based sensor is commonly used in the automotive climate control system to measure the solar radiation exposure of the passenger compartment of a vehicle. The erroneous information from a sensor however can cause thermal discomfort to the occupants. The erroneous measurement can be due to physical or environmental parameters. Shading of a solar sensor due to the opaque vehicle body elements is one such environmental parameter that is known to give incorrect measurement.
2015-04-14
Journal Article
2015-01-0460
Saket Kansara, Sumeet Parashar, Zhendan Xue
Abstract Decision making in engineering design is complicated, especially when dealing with high-dimensional data. Modern software tools are able to produce a large amount of data while performing optimization studies. A typical optimization problem with many objectives may produce 100s or even 1000s of Pareto Optimal solutions. It is a challenge to analyze this data and make a decision about which design/s to choose for further testing or as a final design. To tackle the problem, two data analysis techniques are used in this paper. Partitive Clustering (PC) is used to locate groups of similar designs in the dataset while Principal Component Analysis (PCA) is used to reduce the dimensionality of the data and visualize it in two and three dimensions. Although these techniques can be used independently, when used together, they prove to be a tremendous help in decision making. This paper underlines the benefit of using these two methods together.
2015-04-14
Journal Article
2015-01-1040
Harsha K. Nanjundaswamy, Joel Deussen, Roger Van Sickle, Dean Tomazic, Tamas Szailer, Michael Franke, Matthias Kotter, Thomas Koerfer
Abstract Upcoming motor vehicle emission regulations, such as California's LEVIII, continue to tighten emission limitations in diesel vehicles. These increasingly challenging emission requirements will be met by improving the combustion process (reducing engine-out emissions), as well as improving the exhaust gas aftertreatment efficiency. Furthermore, intricate On-Board Diagnostics (OBD) systems are required to properly diagnose and meet OBD regulation requirements for complex aftertreatment systems. Under these conditions, current monitoring strategies are unable to guarantee reliable detection of partially failed systems. Additionally, new OBD regulations require aftertreatment systems to be diagnosed as a whole. This paper covers potential OBD strategies for LEVIII aftertreatment concepts with regard to regulation compliance and robustness, while striving to use existing sensor concepts.
2015-04-14
Journal Article
2015-01-0599
Akhilendra Pratap Singh, Aditya Gupta, Avinash Kumar Agarwal
Abstract Better understanding of flow phenomena inside the combustion chamber of a diesel engine and accurate measurement of flow parameters is necessary for engine optimization i.e. enhancing power output, fuel economy improvement and emissions control. Airflow structures developed inside the engine combustion chamber significantly influence the air-fuel mixing. In this study, in-cylinder air flow characteristics of a motored, four-valve diesel engine were investigated using time-resolved high-speed Tomographic Particle Imaging Velocimetry (PIV). Single cylinder optical engine provides full optical access of combustion chamber through a transparent cylinder and flat transparent piston top. Experiments were performed in different vertical planes at different engine speeds during the intake and compression stroke under motoring condition. For visualization of air flow pattern, graphite particles were used for flow seeding.
2015-04-14
Journal Article
2015-01-0603
Robert A. Smith, Mikel Petty
Abstract Poly(butylene terephthalate) stock with 0, 15, and 30% glass fiber filler, used in the housings of electrical connectors on hybrid and electric vehicles, was examined by creep and stress relaxation for viscous deformation and modulus loss at 25, 75, 125, and 150°C. Sets of virgin and aged samples were examined within each set then compared to each other. Both the virgin and aged samples showed little viscous deformation or modulus reduction at 25°C, which was below the Tg of 40°C. Thermoplastic creep and stress relaxation was observed at the temperatures above Tg with, expectedly, more sample distortion and stiffness loss observed at higher test temperatures and lower filler contents both in virgin and unaged samples. Aged samples became stiffer, and more resistant to irrecoverable strain and stress relaxation than virgin samples indicating connectors to have a “self-healing” aspect through in-service use at elevated temperatures.
2015-04-14
Journal Article
2015-01-1306
Jeremy S. Neubauer, Eric Wood, Ahmad Pesaran
Abstract Battery second use-putting used plug-in electric vehicle (PEV) batteries into secondary service following their automotive tenure-has been proposed as a means to decrease the cost of PEVs while providing low cost energy storage to other fields (e.g., electric utility markets). To understand the value of used automotive batteries, however, we must first answer several key questions related to battery degradation, including: How long will PEV batteries last in automotive service? How healthy will PEV batteries be when they leave automotive service? How long will retired PEV batteries last in second-use service? How well can we best predict the second-use lifetime of a used automotive battery? Under the support of the U.S. Department of Energy's Vehicle Technologies Office, the National Renewable Energy Laboratory has developed a methodology and the requisite tools to answer these questions, including the Battery Lifetime Simulation Tool (BLAST).
2015-04-14
Journal Article
2015-01-1379
Hideki Matsumura, Shinichiro Itoh, Kenichi Ando
Recently, lithium ion cells are being used in more and more electric and hybrid motor vehicles. However, accidents due to thermal runaway of the cells have been reported, involving abnormal heat, smoke, and fire. Since each of these vehicles contains many cells, if the thermal runaway of one cell triggers that of another and thus causes thermal runaway propagation, a car fire or other serious accident may occur. This study aims to ensure the safety of motor vehicles with lithium ion cells. To identify such accident risks, we conducted a basic experiment to clarify the phenomenon of thermal runaway propagation following a thermal runaway. In the experiment, seven laminate-type lithium ion cells were tightly stacked one on another, with a thermocouple placed at the center of the surface of each cell. Then, the center of the cell in the middle of the seven stacked cells was overcharged to trigger a thermal runaway.
2015-04-14
Journal Article
2015-01-1389
Yu Zhang, Linda Angell, Silviu Pala, Ifushi Shimonomoto
Abstract Objective tools that can assess the demands associated with in-vehicle human machine interfaces (HMIs) could assist automotive engineers designing safer interaction. This paper presents empirical evidence supporting one objective assessment approach, which compares the demand associated with in-vehicle tasks to the demand associated with “benchmarking” or “comparison tasks”. In the presented study, there were two types of benchmarking tasks-a modified surrogate reference task (SuRT) and a delayed digit recall task (n-back task) - representing different levels of visual demand and cognitive demand respectively. Twenty-four participants performed these two types of benchmarking tasks as well as two radio tasks while driving a vehicle on a closed-loop test track. Response measures included physiological (heart rate), glance metrics, driving performance (steering entropy) and subjective workload ratings.
2015-04-14
Journal Article
2015-01-1400
Umashankar Nagarajan, Ambarish Goswami
Abstract The number of seniors is rising worldwide. Exoskeleton devices can help seniors regain their lost power, balance, and agility, thus improving their quality of life. Exoskeleton devices and control strategies assist human gait. A common strategy is to use oscillator-based controllers, which “lock in” with the gait and help the subject walk faster using a phase lead characteristic. Such strategies are limited to gait assist only and are less effective in more general movements. These controllers can be detrimental in critical cases such as when the leg needs to execute a fast reactive stepping to stop a fall. We present a control strategy for a hip exoskeleton, which assists human leg motion by providing motion amplification at the hip joint. The controller is “neutral” because it assists any leg motion, not only a gait, and can help avoid falls by assisting reactive stepping.
2015-04-14
Journal Article
2015-01-0152
Rafal Tomasz Dlugosz, Michał Szulc, Marta Kolasa, Pawel Skruch, Krzysztof Kogut, Paweł Markiewicz, Mateusz Orlowski, Maciej Różewicz, Anna Ryszka, Dominik Sasin, Tomasz Talaska
Abstract In this paper we present an example design process of filters used in automotive industry. Signal preprocessing is very important operation in active safety algorithms. Such algorithms usually take into account the vehicle state that includes position, velocities and accelerations of the car. On the basis of these data, as well as the parameters and trajectories of external objects “observed” by the car, the algorithms make decisions about various safety actions. Designer of such algorithms must assure an appropriate quality of such signals, which usually means a proper filtering. In this paper we focus on selected important aspects of the filter design process. The main objectives of the presented investigations is to obtain such filters that ensure a sufficient rejection of undesired components from the signal and at the same time that do not introduce too high delay to the processed signals.
2015-04-14
Journal Article
2015-01-0154
Lei Rao
The ability to provide a tool integrated environment for quick exploration and optimization of system architecture design alternatives is of paramount importance to the automotive industry. An integrated analysis environment can help reduce development and production costs as well as production time to the market. Given a large number of design alternatives, engineers cannot evaluate them manually due to time constraints. Thus a flexible and scalable tool that helps engineers to automatically explore the design space and optimally select a design meeting the design objectives and constraints is a key for succeeding in this area. This paper discusses lessons learned through hands-on experiences with an existing commercial tool and provides in-depth insights of the development process and complexities.
2015-04-14
Journal Article
2015-01-0153
Reinhold Blank
Abstract Today, the electrical and electronic system in vehicles is one of the core systems - with big influence on functionality and quality. And it is - besides the engine - the most expensive part of the vehicle. The ongoing pressure on saving cost (and weight) is also a major challenge to the developers of the E/E system. Every cent saved on a car creates substantial savings, since most systems are applied to platforms with several million cars per year. A cost saving target of $20 per car (without negative influence on the functionality and quality) sounds impossible for most insiders. This presentation identifies some areas where the potential for savings is not (fully) exhausted. For each area there are examples out of the global automotive industry where substantial savings with $10 or more have been achieved. Furthermore, the presentation will propose approaches for “Value engineering” and “Redesign2Cost”.
2015-04-14
Journal Article
2015-01-0156
Alexandr Murashkin, Luis Silva Azevedo, Jianmei Guo, Edward Zulkoski, Jia Hui Liang, Krzysztof Czarnecki, David Parker
Abstract The number of software-intensive and complex electronic automotive systems is continuously increasing. Many of these systems are safety-critical and pose growing safety-related concerns. ISO 26262 is the automotive functional safety standard developed for the passenger car industry. It provides guidelines to reduce and control the risk associated with safety-critical systems that include electric and (programmable) electronic parts. The standard uses the concept of Automotive Safety Integrity Levels (ASILs) to decompose and allocate safety requirements of different stringencies to the elements of a system architecture in a top-down manner: ASILs are assigned to system-level hazards, and then they are iteratively decomposed and allocated to relevant subsystems and components. ASIL decomposition rules may give rise to multiple alternative allocations, leading to an optimization problem of finding the cost-optimal allocations.
2015-04-14
Journal Article
2015-01-0163
Madhura Medikeri, Thomas Tasky, Johannes Richenhagen
Abstract With the increasing popularity of seamless gear changing and smooth driving experience along with the need for high fuel efficiency, transmission system development has rapidly increased in complexity. So too has transmission control software while quality requirements are high and time-to-market is short. As a result, extensive testing and documentation along with quick and efficient development methods are required. FEV responds to these challenges by developing and integrating a transmission software product line with an automated verification and validation process according to the concept of Continuous Integration (CI). Hence, the following paper outlines a software architecture called “PERSIST” where complexity is reduced by a modular architecture approach. Additionally, modularity enables testability and tracking of quality defects to their root cause.
2015-04-14
Journal Article
2015-01-0177
Thomas Fuhrman, Shige Wang, Marek Jersak, Kai Richter
Abstract Multi-core systems are promising a cost-effective solution for (1) advanced vehicle features requiring dramatically more software and hence an order of magnitude more processing power, (2) redundancy and mixed-IP, mixed-ASIL isolation required for ISO 26262 functional safety, and (3) integration of previously separate ECUs and evolving embedded software business models requiring separation of different software parts. In this context, designing, optimizing and verifying the mapping and scheduling of software functions onto multiple processing cores becomes key. This paper describes several multi-core task design and scheduling design options, including function-to-task mapping, task-to-core allocation (both static and dynamic), and associated scheduling policies such as rate-monotonic, criticality-aware priority assignment, period transformation, hierarchical partition scheduling, and dynamic global scheduling.
2015-04-14
Journal Article
2015-01-0168
Steffen Lampke, Simon Schliecker, Dirk Ziegenbein, Arne Hamann
Abstract The underlying theories of both control engineering and real-time systems engineering assume idealized system abstractions that mutually neglect central aspects of the other discipline. Control engineering theory, on the one hand, usually assumes jitter free sampling and constant input-output latencies disregarding complex real-world timing effects. Real-time engineering theory, on the other hand, uses abstract performance models that neglect the functional behavior, and derives worst-case situations that have little expressiveness for control functionalities in physically dominated automotive systems. As a consequence, there is a lot of potential for a systematic co-engineering between both disciplines, increasing design efficiency and confidence. We have taken a standard control-engineering tool, Simulink, and combined it with state-of-the-art real-time system design and analysis tools, SymTA/S and TraceAnalyzer from Symtavision.
2015-04-14
Journal Article
2015-01-0183
Georg Macher, Muesluem Atas, Eric Armengaud, Christian Kreiner
Abstract Automotive embedded systems have become very complex, are strongly integrated, and the safety-criticality and real-time constraints of these systems raise new challenges. The OSEK/VDX standard provides an open-ended architecture for distributed real-time capable units in vehicles. This is supported by the OSEK Implementation Language (OIL), a language aiming at specifying the configuration of these real-time operating systems. The challenge, however, is to ensure consistency of the concept constraints and configurations along the entire product development. The contribution of this paper is to bridge the existing gap between model-driven systems engineering and software engineering for automotive real-time operating systems (RTOS). For this purpose a bidirectional tool bridge has been established based on OSEK OIL exchange format files.
2015-04-14
Journal Article
2015-01-0179
Ralph Mader, Armin Graf, Gerd Winkler
Abstract The combustion engine will be the dominant drive for motor vehicles despite all the advances in the electrification of the drive train, for many years. The greater are the challenges for the automotive industry, especially in fuel consumption (CO2) and the environmental impacts of other emissions. From the fuel supply to the engine, up to the exhaust after treatment, new or improved functions are needed, which are integrated into increasingly powerful control electronics. This modern electronic engine management and powertrain controller will remain key components in the vehicle. As most of the micro controllers for future applications will be MultiCores, this paper gives an overview on how PowerSAR® supports this kind of architectures. It shows the concepts applied in the basic software area as well as for the applicative software. Further it will show the impact on the development process as well as the integration support for software delivered by the OEM.
2015-04-14
Journal Article
2015-01-0196
Varun M. Navale, Kyle Williams, Athanassios Lagospiris, Michael Schaffert, Markus-Alexander Schweiker
Abstract This paper presents an overview of the evolution & revolution of automotive E/E architectures and how we at Bosch, envision the technology in the future. It provides information on the bottlenecks for current E/E architectures and drivers for their evolution. Functionalities such as automated driving, connectivity and cyber-security have gained increasing importance over the past few years. The importance of these functionalities will continue to grow as these cutting-edge technologies mature and market acceptance increases. Implementation of these functionalities in mainstream vehicles will demand a paradigm shift in E/E architectures with respect to in-vehicle communication networks, power networks, connectivity, safety and security. This paper expounds on these points at a system level.
2015-04-14
Journal Article
2015-01-0194
Hua Zeng, Isao Hoda, William Ivan, Andrew Baker, Syed Kadry, Hiroki Funato, Jia Li, Masayoshi Takahashi, Hideyuki Sakamoto, Ryuichi Saito
Abstract Electromagnetic compatibility (EMC) is becoming more important in power converters and motor drives as seen in hybrid electric vehicles (HEV) to achieve higher reliability of the vehicle and its components. Electromagnetic interference (EMI) of the electronic components for a vehicle are evaluated and validated at a component-level test bench; however, it is sometimes observed that the EMI level of the components can be changed in a vehicle-level test due to differences in the vehicle's configuration (cable routing, connecting location etc.). In this presentation, a vehicle-level EMC simulation methodology is introduced to estimate radiated emissions from a vehicle. The comparison between the simulation and measurement results is also presented and discussed.
2015-04-14
Journal Article
2015-01-0200
Karsten Schmidt, Udo Dannebaum, Harald Zweck
Abstract In-vehicle communication faces increasing bandwidth demands, which can no longer be met by today's MOST150, FlexRay or CAN networks. In recent years, Fast Ethernet has gained a lot of momentum in the automotive world, because it promises to bridge the bandwidth gap. A first step in this direction is the introduction of Ethernet as an On Board Diagnostic (OBD) interface for production vehicles. The next potential use cases include the use of Ethernet in Driver Assistance Systems and in the infotainment domain. However, for many of these use cases, the Fast Ethernet solution is too slow to move the huge amount of data between the Domain Controllers, ADAS Systems, Safety Computer and Chassis Controller in an adequate way. The result is the urgent need for a network technology beyond the Fast Ethernet solution. The question is: which innovation will provide enough bandwidth for domain controllers, fast flashing routines, video data, MOST-replacement and internal ECU buses?
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