This paper deals with bandwidth requirement estimates in buffered statistical multiplexers with the underlying many sources asymptotics modeling framework. Within this multiplexer model refined approximation for buffe...
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This paper deals with bandwidth requirement estimates in buffered statistical multiplexers with the underlying many sources asymptotics modeling framework. Within this multiplexer model refined approximation for buffered workload loss ratio is considered. Based on this direct and computationally feasible equivalent bandwidth requirement estimator is presented in full accordance with the corresponding QoS constraint.
This paper presents an adaptive, heart-model-based ECG compression method. After a conventional pre-filtering the waves from the signal are localized and the model's parameters are determined. The structure of the...
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This paper presents an adaptive, heart-model-based ECG compression method. After a conventional pre-filtering the waves from the signal are localized and the model's parameters are determined. The structure of the algorithm allows real-time adaptation to the heart's state. The compression, for better comparison, was performed for one and more channels from the MIT/BIH database samples. The compression ratio depends on the maximal allowed root mean square reconstruction error (RMSRE). As a second classification criterion we applied the performance of the signal detection method from the compacted data. We used an adaptive entropy encoder to reduce the redundancy. The major advantage of this method is the possibility to accomplish a real-time, adaptive and patient specific encoding with relatively low computational power, ideal for telemetry measurements. This research is supported by the Hungarian Foundation for Scientific Research, Grant T29830 and FKFP0301/0999 Project.
In this paper a Rayleigh fading model based reliability-centric routing algorithm is proposed for Wireless Sensor Networks (WSNs). The proposed scheme is optimized with respect to minimal power consumption to improve ...
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In this paper a Rayleigh fading model based reliability-centric routing algorithm is proposed for Wireless Sensor Networks (WSNs). The proposed scheme is optimized with respect to minimal power consumption to improve longevity as well as to ensure reliable packet transmission to the Base Station (BS). Reliability is guaranteed by selecting path over which the probability of correct packet reception of the transmitted packet will exceed a predefined threshold at the BS. It will be pointed out that reliable and power efficient packet forwarding over WSN can be mapped into a constrained optimization problem. This optimization is then reduced to a shortest path problem with specific link metrics solved in polynomial time.
Today's mobile devices are equipped with multiple interfaces to make the connection possible to different type of networks. In order to efficiently utilize the interface capabilities, multi-path streaming can be u...
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Today's mobile devices are equipped with multiple interfaces to make the connection possible to different type of networks. In order to efficiently utilize the interface capabilities, multi-path streaming can be used. Resource intensive applications can deliver high bitrate streams over multiple paths by cumulating the available bandwidth of the different subpaths. In this paper we propose a multi-path streaming method that chooses a set of paths maximizing the overall quality at the client. While the available paths have different bandwidth, delay and loss probability constrains, the packet distributor must take the video packet importance and the dependencies between packets into account. Transmitting the reference video frames on the most reliable links will decrease the loss probability of important data packets and increase the measured video quality. Both analytical and simulation analysis were performed to examine the behavior of the presented content-aware interface selection model. The results show that the proposed solution provides higher video quality than common scheduling algorithms.
An exact and general performance analysis has been introduced for M-QAM modulation in terms of bit error ratio (BER) and transmission rate assuming gray mapping. BER expressions have been derived for different fading ...
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An exact and general performance analysis has been introduced for M-QAM modulation in terms of bit error ratio (BER) and transmission rate assuming gray mapping. BER expressions have been derived for different fading channel types (Rayleigh, Rice and Nakagami). The analyzed transmission considers OFDM interference, which is influenced by Rayleigh fading channel. During the calculation, the spectral shapes of the victim and interfering signals are also considered. The BER expressions have also been applied for LTE, giving a tool for the evaluation of LTE physical layer performance in adjacent channel interference scenarios.
An enterprise resource planning (ERP) system is defined as a unified information system, performing all information-processing tasks of a company and realizing an integration of the whole corporation. The aimed scope ...
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An enterprise resource planning (ERP) system is defined as a unified information system, performing all information-processing tasks of a company and realizing an integration of the whole corporation. The aimed scope of duties indicates that these software products are very complex regarding their structure and operation. What is more, ERP systems are almost always standard software products. The parametrizable and configurable structure increases their complexity. We analyse these complex software products. We examine the users' needs and the life-cycle of these systems, determine their components according to the three tier architecture and summarize the requirements against these parts.
In the area of high voltages and powers, the high quality inverter-fed ac drive is more easily achieved by the use of three-level inverters. For three-level inverters three different PWM control regions can be introdu...
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In the area of high voltages and powers, the high quality inverter-fed ac drive is more easily achieved by the use of three-level inverters. For three-level inverters three different PWM control regions can be introduced where different two-phase (discontinuous) PWM strategies may be applied. This paper deals with the analysis of voltage spectra of one discontinuous PWM method of three-level inverters when every 60deg of each fundamental period the one motor phase is clamped to dc bar. The derivation of the analytical equations of motor voltage harmonics for this PWM method is given for both realizations: with one and with two carrier waves. The comparison of the voltage spectra of the possible PWM methods is presented. It is shown that in the low voltage area the same value of motor harmonic losses are produced for both one and two carrier wave solutions. However, for the high voltage area the harmonic losses associated with the two carrier modulation are usually considerably lower than in case of one carrier method. The two carrier method can be disadvantageous only for low modulation frequency when the low order harmonics reach the sensitive value
In this paper a new low cost design is presented. The moving element of the probe head consists of the stylus fixed to a diaphragm flexure, made of berillium-copper foil with, a small aluminium enhanced mirrors at the...
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In this paper a new low cost design is presented. The moving element of the probe head consists of the stylus fixed to a diaphragm flexure, made of berillium-copper foil with, a small aluminium enhanced mirrors at the center. The displacement of the probe tip is determined from the displacement and the rotations of the mirrors measured by a modified optical pick-up and by two lasers focused on four quadrant diodes. In order to test probes a calibration system with ~40 nm measuring uncertainty was designed. A high precision three-axis translation stage, with a working range of 100 times 100 times 100 mum, moves the probe stylus and the position of the stage is determined by three mutually-orthogonal plane mirror laser interferometer transducers having 1 nm resolution.
Due to legislation and market trends, every electronic appliance assembler has to change leaded solders to lead free. In recent years, a number of manufacturers were simply waiting, and they know little or nothing abo...
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Due to legislation and market trends, every electronic appliance assembler has to change leaded solders to lead free. In recent years, a number of manufacturers were simply waiting, and they know little or nothing about the behavior of lead free solders. However, there is now a necessity for lead free solders because the RoHS and WEEE directives are coming into effect by July 2006. To bring to light the particular differences between widely used industrial SnPbAg and SnAgCu solders, a test PCB for conventional SMT devices was designed and experimental soldering was done by IR reflow technology with both alloys.
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