An architectural solution to reducing energy consumption of flash-memory storage system is to take advantage of a multi-bank architecture instead of a single-bank one. thus, allowing unused banks to be placed into low...
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ISBN:
(纸本)0769523463
An architectural solution to reducing energy consumption of flash-memory storage system is to take advantage of a multi-bank architecture instead of a single-bank one. thus, allowing unused banks to be placed into low-power operating modes can help reduce energy. In this paper an adaptive energy-aware bank assignment policy is proposed to cluster data with temporal affinity into the same bank, increasing the number of banks put into low-power modes. then we propose an energy-aware garbage collection policy, which could keep banks in idle conditions for long durations of time to compensate for resynchronization penalties. Experiments over the prototype show the effectiveness of these policies and indicate that large energy savings can be achieved with low overhead.
We analyze the execution time of MAC-layer Reed-Solomon error recovery in cdma2000 1xEV-DO broadcast and multicast services (BCMCS), with respect to cache size and air channel condition. We observe that a deterioratin...
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ISBN:
(纸本)0769523463
We analyze the execution time of MAC-layer Reed-Solomon error recovery in cdma2000 1xEV-DO broadcast and multicast services (BCMCS), with respect to cache size and air channel condition. We observe that a deteriorating channel condition often causes an intolerable delay for real-time tasks because of the error recovery process, even when sufficient cache memory is available to increase CPU throughput. To overcome this problem, we propose proactive Reed-Solomon bypass (PRSB), which determines whether the Reed-Solomon scheme should be used to correct errors in the real-time communication environment. the proposed scheme utilizes the cache effectively, thus preventing reset of the entire decoding process and allowing real-time multimedia applications to meet their deadline constraints. Simulation results show that the PRSB greatly improves the overall playback quality of a video.
We address in this paper the problem of scheduling for multiprocessor real-timesystems with hard and soft tasks. Utility functions are associated to soft tasks to capture their relative importance and how the quality...
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ISBN:
(纸本)0769523463
We address in this paper the problem of scheduling for multiprocessor real-timesystems with hard and soft tasks. Utility functions are associated to soft tasks to capture their relative importance and how the quality of results is affected when a soft deadline is missed. the problem is to find a task execution order that maximizes the total utility and guarantees the hard deadlines. In order to account for actual execution times, we consider time intervals for tasks rather than fixed execution times. A single static schedule computed off-line is pessimistic, while a purely on-line approach, which computes a new schedule every time a task completes, incurs an unacceptable overhead. We propose therefore a quasi-static solution where a number of schedules are computed at design-time, leaving for run-time only the selection of a particular schedule, based on the actual execution times. We propose an exact algorithm as well as heuristics that tackle the time and memory complexity of the problem. We evaluate our approach through synthetic examples and a realistic application.
We propose a new architecture for a content protection system that conceals confidential data and algorithms in an FPGA as electrical circuits. this architecture is designed for a client-server type on-line contents d...
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ISBN:
(纸本)0769523463
We propose a new architecture for a content protection system that conceals confidential data and algorithms in an FPGA as electrical circuits. this architecture is designed for a client-server type on-line contents distribution services. the key component of this architecture is the digital content security circuit that is dynamically configured on the FPGA and performs the signal processing such as certification and decryption for replaying digital contents. the digital content security circuit is composed of two different circuits. One is the content-specific circuit that is built from the configuration data generated by the server. this circuit is specialized for each item of digital content. the other is the terminal built-in circuit that is uniquely programmed and implemented for each terminal, and is not open for the others. the content-specific circuit properly work only if it is combined withthe terminal built-in circuit of the authorized client. We prototype and demonstrate a proof-of-concept model of the FPGA-based content protection system applicable to embedded consumer electronics such as set top boxes and cell phones.
the run-time power consumption model for multimedia application routines in an embedded system is developed in this work. A wide range of benchmarks for these routines such as image, video and speech coding algorithms...
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the real-time Specification for Java (RTSJ) offers the predictable memory management needed for real-timeapplications, while maintaining Java's advantages of portability and ease of use. RTSJ's scoped memory ...
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ISBN:
(纸本)0769523463
the real-time Specification for Java (RTSJ) offers the predictable memory management needed for real-timeapplications, while maintaining Java's advantages of portability and ease of use. RTSJ's scoped memory allows object lifetimes to be controlled in groups, rather than individually as in C++. While easier than individual object lifetime management, scoped memory adds programming complexity from strict rules governing memory access across scopes. Moreover memory leaks can potentially create jitter and reduce performance. To manage the complexities of RTSJs scoped memory, we developed patterns and tools for RTZen, a real-time CORBA Object Request Broker (ORB). We describe four new patterns that enable communication and coordination across scope boundaries, an otherwise difficult task in RTSJ. We then present IsoLeak, a runtime debugging tool that visualizes the scoped hierarchies of complex applications and locates memory leaks. Our empirical results show that RTZen is highly predictable and has acceptable performance. RTZen therefore demonstrates that the use of patterns and tools like IsoLeak can help applications meet the stringent QoS requirements of DRE applications, while supporting safer easier cheaper and faster development in real-time Java.
Dynamic voltage scaling (DVS) and dynamic power management (DPM) are widely-used techniques to reduce energy consumption in modern computingsystems. Although combining these techniques can save more energy, there has...
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Data broadcast is an efficient information delivery model that can deliver information to a large population simultaneously. In this paper, we propose two efficient algorithms to broadcast real-time and non-real-time ...
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Since the lifetime of a battery directly impacts the lifetime of sensor networks, one of the key considerations in the design of sensor networks is the ability to maximize battery lifetime. In this paper, we present (...
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Due to the increasing demand for quick time-to-market and diverse functionalities in the development of powertrain controllers, the traditional vehicle development process must be replaced with a model-based process. ...
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